This document summarizes research on the precipitation behavior and heterogeneous nucleation effects of V(C, N) particles in vanadium microalloyed steel. The researchers found that V(C, N) particles promote the nucleation of intragranular ferrite in two ways: 1) the high coherency between V(C, N) and ferrite causes V(C, N) to act as nucleation sites for ferrite, and 2) coarsening of V(C, N) creates locally solute-depleted regions in austenite that further expedite ferrite nucleation. Additionally, the study observed a phenomenon of "wrapped ferrite" where smaller ferrite grains nucleate within
Structure, microstructure and dielectric study of (ba0.6 sr0.4)(zr0.6ti0.4)o3...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Some studies on ceria–zirconia reinforced solvothermally synthesized cordieri...Abhinav Srivastava
Nanostructured cordierite and 12 mol% ceria stabilized zirconia were chemically prepared separately. Pure cordierite was synthesized solvothermally, whereas [(Zr)0.88(Ce)0.12O2] termed as CeSZ was processed with gelation and co-precipitation method. The evolution of crystalline phases and the microstructures have been studied using X-ray diffractometer, and FE-SEM with EDX. Varying contents (0–20 weight%) of CeSZ were then mixed with cordierite to form sample blocks of desired shapes. These nano-composite blocks were fired at 1100–1400 C for a soaking time of 3 h to observe their thermomechanical, micro-structural and physical properties. Results indicate that ceria not only acts as a stabilizer in zirconia ceramics but it also acts as a sintering aid in cordierite formation. CeO2 also improves
compressibility and structural properties of nano-composites. Sintering temperature also plays an important role in the behavior of nano-composite blocks. All properties show a major improvement than previous reported data’s.
Microstructural Analysis of the Influence of Ecap on the Pure Nb Rolling PlaneIJERA Editor
Starting From a sample of pure and pre-deformed niobium by cold rolling a severe plastic deformation process was performed using ECAP (equal channel angular pressing) in order to verify the evolution and distibution of the deformation structures and of hardness in the lamination plane of the material. To make the analysis were used: the Scanning Electron Microscope-SEM, optical microscope and a hardness map to have a better view of how homogeneous or heterogeneous a process is in relation to the other. After comparison it was seen that the process through ecap uniformized the microstructure and hardness of the material.
High manganese conference korea twip steelDierk Raabe
Lecture about the effects of strain path and crystallographic texture on microstructure in Fe–22 wt.% Mn–0.6 wt.% C TWIP steels using Electron Channeling Contrast Imaging (ECCI) and EBSD
Structure, microstructure and dielectric study of (ba0.6 sr0.4)(zr0.6ti0.4)o3...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Some studies on ceria–zirconia reinforced solvothermally synthesized cordieri...Abhinav Srivastava
Nanostructured cordierite and 12 mol% ceria stabilized zirconia were chemically prepared separately. Pure cordierite was synthesized solvothermally, whereas [(Zr)0.88(Ce)0.12O2] termed as CeSZ was processed with gelation and co-precipitation method. The evolution of crystalline phases and the microstructures have been studied using X-ray diffractometer, and FE-SEM with EDX. Varying contents (0–20 weight%) of CeSZ were then mixed with cordierite to form sample blocks of desired shapes. These nano-composite blocks were fired at 1100–1400 C for a soaking time of 3 h to observe their thermomechanical, micro-structural and physical properties. Results indicate that ceria not only acts as a stabilizer in zirconia ceramics but it also acts as a sintering aid in cordierite formation. CeO2 also improves
compressibility and structural properties of nano-composites. Sintering temperature also plays an important role in the behavior of nano-composite blocks. All properties show a major improvement than previous reported data’s.
Microstructural Analysis of the Influence of Ecap on the Pure Nb Rolling PlaneIJERA Editor
Starting From a sample of pure and pre-deformed niobium by cold rolling a severe plastic deformation process was performed using ECAP (equal channel angular pressing) in order to verify the evolution and distibution of the deformation structures and of hardness in the lamination plane of the material. To make the analysis were used: the Scanning Electron Microscope-SEM, optical microscope and a hardness map to have a better view of how homogeneous or heterogeneous a process is in relation to the other. After comparison it was seen that the process through ecap uniformized the microstructure and hardness of the material.
High manganese conference korea twip steelDierk Raabe
Lecture about the effects of strain path and crystallographic texture on microstructure in Fe–22 wt.% Mn–0.6 wt.% C TWIP steels using Electron Channeling Contrast Imaging (ECCI) and EBSD
Annealing and Microstructural Characterization of Tin-Oxide Based Thick Film ...Anis Rahman
Abstract. The sheet resistance of tin oxide based thick-film resistors exhibits two regions of temperature dependence,
described by hopping (23°C-200°C) and diffusion mechanisms (200°C-350°C), respectively.
Annealing these samples causes the sheet resistance to increase in both regions. In the post-annealed samples,
the hopping conduction range is extended by 50°C (23°C-250°C) while the hopping parameter, To, is decreased by
more than 50%. The activation energy of diffusion (0.60 eV) is the same for both pre- and post annealed samples, but
the magnitude of resistance in the diffusion controlled region is increased significantly as a result of annealing. These
changes are explained in terms of a net decrease in the concentration of tin ions in the glass matrix. From a careful
microstructural study it was found that a conduction path composed of tin-oxide grains or their clusters in contact
with each other does not exist in the present system. HREM micrographs showed the presence of nanocrystalline
tin-oxide particles in the glass phase separating the tin-oxide grain clusters. Estimated average separation between
the nanocrystals in 4 nm, consistent with a variable-range hopping conduction via the dissolved tin ions in the glass
matrix.
OPTICAL BEHAVIOUR OF SYNTHESIZED ZNO NANOTABLETS AND ITS TRANSFORMED NANORODS...antjjournal
We are reporting the preparation of ZnO nanotablets at relatively low temperature (1500C) using zinc acetate [Zn(Ac)2], NaOH, cetyltrimethylammonium bromide (CTAB) by solvothermal method. By adjusting
the molar ratio of the reactants we obtained nanorods and we also obtained the variation of the dimension
of the nanorods using hydrazine hydrate as capping reagent. The prepared samples were morphologically
recognized as well crystallized. The average diameter of the ZnO nanotablets were ranging from 500 to 600 nm and the average thickness of the nanotablets were ranging from 85 to 90 nm. The length of ZnO nanorods were ranging from 300 to several micrometers and breadth of the ZnO nanorods were ranging from 80 to 160 nm. The optical properties of the prepared materials have also been studied with the exhibition of its interesting behavior.
Structural Stability of Nano-Crystalline Aluminum-Glass CompositesIOSRJAP
Effects of particle size of the material in nanometer on solid state, structural properties AluminumGlass based samples are reported in this study. The particle size of 25µm was used for both Aluminum and Glass powders respectively. The samples were prepared in powdered form of various Al-Glass proportions. The weight of Aluminum ranges between 20 – 60 percent in the composites. Results showed from X-ray diffraction analyses that Aluminum addition and the determined particle size greatly influence the structural stability of the samples. It was revealed that samples were structurally stable in the range of Aluminum composition and the observed size of crystals, measured Width at Middle of Maximum Height and structural parameters were found in nanometers. The Al-Glass materials were noted to crystallize with FCC and BCC lattice structures.
Correlation between the Interface Width and the Adhesion Strength of Copper F...IOSRJAP
The present study has been conducted in order to determine the influence of negative bias voltage applied to substrate on adhesion of copper films deposited on carbon steel substrates. The adhesion strength has been evaluated by the scratch test. Coatings were deposited by a DC magnetron sputtering system. The substrates were firstly mechanically polished and then ion-etched by argon ions prior to deposition. Adhesion was found to increase with the bias voltage. The critical load had a value of 9.5 g for an unbiased substrate and reached 18.5 g for a bias voltage of 600 V. Equally important, the interface width, measured using Auger electron spectroscopy, increased as a function of the bias voltage. The width of the interface is related to the time of ion milling in the Auger spectrometer. The size of this width is obtained from the Auger elemental depth profiles through measuring the depth of the interface coating/substrate. The width had a value of 335 min with a bias of 600 V whereas it didn't exceed 180 min when the substrate was unbiased. Therefore, the effect of the bias voltage was to expand the interface because of the diffusion phenomenon and physical mixing of materials at the interface. Moreover, the critical load increased with the increase of the interface width.
Preparation and Investigation on Properties of Cryogenically Solidified Nano ...IJERA Editor
In the present work, AL-alloy containing 12% silicon (LM 13) matrix nano composites were fabricated in sand moulds by using copper end blocks of copper end chill thickness 10 &15 nm with cryogenic effect . The size of the reinforcement (NanoZro2) ranges from 50-80nm being added ranges from 3 to 15 wt % in steps of 3 wt % . Cryogenically solidified Nano Metal Matrix Composites were compressed by using hydraulic compression machine. Specimens were prepared according to ASTM standards and tested for their strength, hardness and fracture toughness. Micro structural studies of the fabricated Nano Composites indicate that there is uniform distributions of reinforcements in the matrix materials (LM 13). An increasing trend of hardness, UTS & fracture toughness has been observed. The best results have been obtained at 12 wt %. The results were further justified by comparing two copper end chill thickness 10 &15 mm. Finally the Volumetric Heat Capacity of the cryo-chill is identified as an important parameter which affects mechanical properties.
Microstructural Characterization of Co-Cr-Mo-W Alloy as Casting for Odontolog...IJERA Editor
Interest in the analysis and material characterization is rising due to the necessity of the adequate material selection based on system performance in study. The analysis and knowledge of the microstructure and the mechanical properties of any material are of utmost importance since it aims primarily to estimate the performance during the material life span, minimizing the possibility of degradation and undesirable flaws during product utilization. Co-Cr-Mo-W alloys have been well accepted in odontology as prosthesis material, due to its high mechanical resistance, good corrosion resistance and exceptional biocompatibility properties. This study aims to characterize the microstructure of a cobalt based alloy (Co-Cr-Mo-W) obtained through vacuum casting process. Optical microscopy, electronic sweeping microscopy and X-ray were employed and Vickers hardness test with loads of 100 gf, 500 gf and 1000 gf during 10 s. Microstructure casting is characterized by a Co-fcc dendritic matrix with a secondary phase, as well as M23C6 precipitate carbides in the interdendritics zones and grain boundaries. The precipitation of carbides represents the main device of strengthening in the cast state for these types of alloys and is also responsible for its lower mechanical properties. The material attained hardness between 25 and 35 HRC, meeting the ASTM F75 standards.
International Refereed Journal of Engineering and Science (IRJES)irjes
a leading international journal for publication of new ideas, the state of the art research results and fundamental advances in all aspects of Engineering and Science. IRJES is a open access, peer reviewed international journal with a primary objective to provide the academic community and industry for the submission of half of original research and applications.
Stress Annealed CoFeNbB Alloy : A Structural Studyijtsrd
Article presents the influence of Nb content on structural properties of stress annealed Co21Fe64-xNbxB15 (x = 3, 5, 7) alloys has been studied using differential scanning calorimetery, in-situ length change measurements during annealing and x-ray diffraction. Results show that, increase of Nb content in the alloy increases the stability of the alloy against crystallization and is also responsible for higher elongation of the specimens. Crystallization leads to the formation of bcc Fe-Co nano-granular phase containing Co up to 38 % and affects the spin texture. Shailendra Singh Khinchi"Stress Annealed CoFeNbB Alloy : A Structural Study" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-1 | Issue-5 , August 2017, URL: http://www.ijtsrd.com/papers/ijtsrd2271.pdf http://www.ijtsrd.com/physics/engineering-physics/2271/stress-annealed-cofenbb-alloy--a-structural-study/shailendra-singh-khinchi
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Optical and surface properties of al doped ga2 o3 by elemental stack methodeSAT Journals
Abstract Al doped Ga2O3 thin film was prepared by stacking of Al thin film on Ga2O3 thin film using thermal evaporator. The doping process was carried out by post annealing process at three different temperatures. The absorbance spectra revealed the Al doping process and showed low absorbance at high annealing temperature. Scanning Electron Microscope images were the evidence of surface effect due to Al diffuses at high annealing temperature (> 400°C). Energy Dispersive Spectra showed the changes in the elemental composition of Al doped Ga2O3 thin film for various annealing temperature and revealed Al diffusion by observed low Al content at the surface of the doped Ga2O3 thin film. Keywords: Ga2O3, Al doping, Optical properties, Surface analysis
Wear and Corrosion Study of Sputtered Zirconium thin films on SS316L for Wind...IJERA Editor
The Aim of this study is to observe the Wear and Corrosion behavior of Zirconium coated 316L stainless steel. After polishing, SS316L was coated with Zirconium employing DC sputtering process (a technique of physical vapor deposition).Structure characterization techniques including Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD) were utilized to investigate the microstructure and crystallinity of the coating. Salt spray test was performed by spraying Sodium chloride in order to determine corrosion resistance behavior of the coated sample. Pin on disc wear test was performed by hardened and tempered EN31 steel pin in order to determine and compare the Wear resistance behavior of Coated and uncoated samples. The Objective is to recommend the zirconium coated Stainless steel SS316L can be a choice for Off-shore wind mills where the shafts undergo Wear and corrosion problems.
Dislocation and twin substructure evolution during strain hardening of an Fe–22 wt.% Mn–0.6 wt.% C TWIP steel observed by electron channeling contrast imaging
Annealing and Microstructural Characterization of Tin-Oxide Based Thick Film ...Anis Rahman
Abstract. The sheet resistance of tin oxide based thick-film resistors exhibits two regions of temperature dependence,
described by hopping (23°C-200°C) and diffusion mechanisms (200°C-350°C), respectively.
Annealing these samples causes the sheet resistance to increase in both regions. In the post-annealed samples,
the hopping conduction range is extended by 50°C (23°C-250°C) while the hopping parameter, To, is decreased by
more than 50%. The activation energy of diffusion (0.60 eV) is the same for both pre- and post annealed samples, but
the magnitude of resistance in the diffusion controlled region is increased significantly as a result of annealing. These
changes are explained in terms of a net decrease in the concentration of tin ions in the glass matrix. From a careful
microstructural study it was found that a conduction path composed of tin-oxide grains or their clusters in contact
with each other does not exist in the present system. HREM micrographs showed the presence of nanocrystalline
tin-oxide particles in the glass phase separating the tin-oxide grain clusters. Estimated average separation between
the nanocrystals in 4 nm, consistent with a variable-range hopping conduction via the dissolved tin ions in the glass
matrix.
OPTICAL BEHAVIOUR OF SYNTHESIZED ZNO NANOTABLETS AND ITS TRANSFORMED NANORODS...antjjournal
We are reporting the preparation of ZnO nanotablets at relatively low temperature (1500C) using zinc acetate [Zn(Ac)2], NaOH, cetyltrimethylammonium bromide (CTAB) by solvothermal method. By adjusting
the molar ratio of the reactants we obtained nanorods and we also obtained the variation of the dimension
of the nanorods using hydrazine hydrate as capping reagent. The prepared samples were morphologically
recognized as well crystallized. The average diameter of the ZnO nanotablets were ranging from 500 to 600 nm and the average thickness of the nanotablets were ranging from 85 to 90 nm. The length of ZnO nanorods were ranging from 300 to several micrometers and breadth of the ZnO nanorods were ranging from 80 to 160 nm. The optical properties of the prepared materials have also been studied with the exhibition of its interesting behavior.
Structural Stability of Nano-Crystalline Aluminum-Glass CompositesIOSRJAP
Effects of particle size of the material in nanometer on solid state, structural properties AluminumGlass based samples are reported in this study. The particle size of 25µm was used for both Aluminum and Glass powders respectively. The samples were prepared in powdered form of various Al-Glass proportions. The weight of Aluminum ranges between 20 – 60 percent in the composites. Results showed from X-ray diffraction analyses that Aluminum addition and the determined particle size greatly influence the structural stability of the samples. It was revealed that samples were structurally stable in the range of Aluminum composition and the observed size of crystals, measured Width at Middle of Maximum Height and structural parameters were found in nanometers. The Al-Glass materials were noted to crystallize with FCC and BCC lattice structures.
Correlation between the Interface Width and the Adhesion Strength of Copper F...IOSRJAP
The present study has been conducted in order to determine the influence of negative bias voltage applied to substrate on adhesion of copper films deposited on carbon steel substrates. The adhesion strength has been evaluated by the scratch test. Coatings were deposited by a DC magnetron sputtering system. The substrates were firstly mechanically polished and then ion-etched by argon ions prior to deposition. Adhesion was found to increase with the bias voltage. The critical load had a value of 9.5 g for an unbiased substrate and reached 18.5 g for a bias voltage of 600 V. Equally important, the interface width, measured using Auger electron spectroscopy, increased as a function of the bias voltage. The width of the interface is related to the time of ion milling in the Auger spectrometer. The size of this width is obtained from the Auger elemental depth profiles through measuring the depth of the interface coating/substrate. The width had a value of 335 min with a bias of 600 V whereas it didn't exceed 180 min when the substrate was unbiased. Therefore, the effect of the bias voltage was to expand the interface because of the diffusion phenomenon and physical mixing of materials at the interface. Moreover, the critical load increased with the increase of the interface width.
Preparation and Investigation on Properties of Cryogenically Solidified Nano ...IJERA Editor
In the present work, AL-alloy containing 12% silicon (LM 13) matrix nano composites were fabricated in sand moulds by using copper end blocks of copper end chill thickness 10 &15 nm with cryogenic effect . The size of the reinforcement (NanoZro2) ranges from 50-80nm being added ranges from 3 to 15 wt % in steps of 3 wt % . Cryogenically solidified Nano Metal Matrix Composites were compressed by using hydraulic compression machine. Specimens were prepared according to ASTM standards and tested for their strength, hardness and fracture toughness. Micro structural studies of the fabricated Nano Composites indicate that there is uniform distributions of reinforcements in the matrix materials (LM 13). An increasing trend of hardness, UTS & fracture toughness has been observed. The best results have been obtained at 12 wt %. The results were further justified by comparing two copper end chill thickness 10 &15 mm. Finally the Volumetric Heat Capacity of the cryo-chill is identified as an important parameter which affects mechanical properties.
Microstructural Characterization of Co-Cr-Mo-W Alloy as Casting for Odontolog...IJERA Editor
Interest in the analysis and material characterization is rising due to the necessity of the adequate material selection based on system performance in study. The analysis and knowledge of the microstructure and the mechanical properties of any material are of utmost importance since it aims primarily to estimate the performance during the material life span, minimizing the possibility of degradation and undesirable flaws during product utilization. Co-Cr-Mo-W alloys have been well accepted in odontology as prosthesis material, due to its high mechanical resistance, good corrosion resistance and exceptional biocompatibility properties. This study aims to characterize the microstructure of a cobalt based alloy (Co-Cr-Mo-W) obtained through vacuum casting process. Optical microscopy, electronic sweeping microscopy and X-ray were employed and Vickers hardness test with loads of 100 gf, 500 gf and 1000 gf during 10 s. Microstructure casting is characterized by a Co-fcc dendritic matrix with a secondary phase, as well as M23C6 precipitate carbides in the interdendritics zones and grain boundaries. The precipitation of carbides represents the main device of strengthening in the cast state for these types of alloys and is also responsible for its lower mechanical properties. The material attained hardness between 25 and 35 HRC, meeting the ASTM F75 standards.
International Refereed Journal of Engineering and Science (IRJES)irjes
a leading international journal for publication of new ideas, the state of the art research results and fundamental advances in all aspects of Engineering and Science. IRJES is a open access, peer reviewed international journal with a primary objective to provide the academic community and industry for the submission of half of original research and applications.
Stress Annealed CoFeNbB Alloy : A Structural Studyijtsrd
Article presents the influence of Nb content on structural properties of stress annealed Co21Fe64-xNbxB15 (x = 3, 5, 7) alloys has been studied using differential scanning calorimetery, in-situ length change measurements during annealing and x-ray diffraction. Results show that, increase of Nb content in the alloy increases the stability of the alloy against crystallization and is also responsible for higher elongation of the specimens. Crystallization leads to the formation of bcc Fe-Co nano-granular phase containing Co up to 38 % and affects the spin texture. Shailendra Singh Khinchi"Stress Annealed CoFeNbB Alloy : A Structural Study" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-1 | Issue-5 , August 2017, URL: http://www.ijtsrd.com/papers/ijtsrd2271.pdf http://www.ijtsrd.com/physics/engineering-physics/2271/stress-annealed-cofenbb-alloy--a-structural-study/shailendra-singh-khinchi
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Optical and surface properties of al doped ga2 o3 by elemental stack methodeSAT Journals
Abstract Al doped Ga2O3 thin film was prepared by stacking of Al thin film on Ga2O3 thin film using thermal evaporator. The doping process was carried out by post annealing process at three different temperatures. The absorbance spectra revealed the Al doping process and showed low absorbance at high annealing temperature. Scanning Electron Microscope images were the evidence of surface effect due to Al diffuses at high annealing temperature (> 400°C). Energy Dispersive Spectra showed the changes in the elemental composition of Al doped Ga2O3 thin film for various annealing temperature and revealed Al diffusion by observed low Al content at the surface of the doped Ga2O3 thin film. Keywords: Ga2O3, Al doping, Optical properties, Surface analysis
Wear and Corrosion Study of Sputtered Zirconium thin films on SS316L for Wind...IJERA Editor
The Aim of this study is to observe the Wear and Corrosion behavior of Zirconium coated 316L stainless steel. After polishing, SS316L was coated with Zirconium employing DC sputtering process (a technique of physical vapor deposition).Structure characterization techniques including Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD) were utilized to investigate the microstructure and crystallinity of the coating. Salt spray test was performed by spraying Sodium chloride in order to determine corrosion resistance behavior of the coated sample. Pin on disc wear test was performed by hardened and tempered EN31 steel pin in order to determine and compare the Wear resistance behavior of Coated and uncoated samples. The Objective is to recommend the zirconium coated Stainless steel SS316L can be a choice for Off-shore wind mills where the shafts undergo Wear and corrosion problems.
Dislocation and twin substructure evolution during strain hardening of an Fe–22 wt.% Mn–0.6 wt.% C TWIP steel observed by electron channeling contrast imaging
INVESTIGATION OF OXIDATION RESISTANCE OF NI- TI ELECTROCHEMICAL CODEPOSITION ...IAEME Publication
The effects of Ti particle loading in a plating bath on the morphology and hardness of Ni-Ti composite coatings via an electrochemical codeposition coating were investigated. The Ti-reinforced Ni-matrix composite coatings were codeposited on Austenitic Stainless Steel (316 L) substrates using a Ni-ion electrolytic solution stably suspended with -20 m max. diameter Ti particles and heat treated under vacuum atmosphere for six hours at 950 °C prior to oxidation testing.
The objective of this paper is to study the micro
structural features of ZA27alloy containing nickel in the range
from 1 to 3 wt. %. The microstructure of the alloy was examined
using both optical and SEM. High percentage of nickel helps in
imparting strength to the alloy and also to overcome dimensional
instability as it forms various intermetallic compounds containing
hard particles. Small percentage of magnesium in the alloy helps
in reducing intergranular corrosion. The microstructure consists
of small, flaky and rod like irregularly shaped intermetallic
compound in the interdendritic and eutectic regions.
Metallographic studies showed that addition of nickel resulted in
microstructural modifications of the alloy involving the
formation of complex intermetallic compounds α.
Influence of volume fraction, size, cracking, clustering of particulates and ...eSAT Journals
Abstract
The objective of this study is to examine the influence of volume fraction, size of particulates, formation of precipitates at the
matrix/particle interface, particle cracking, voids/porosity, and clustering of particulates on the strength and stiffness of
6063/SiCp metal matrix composites. Tensile strength and stiffness increase with an increase in the volume fraction of SiC
particulates. The tensile strength and stiffness decrease with increase in size of the particulates, presence of porosity, clustering,
and particle cracking. Formation of particulate clusters is more prominent in the composites having very small-reinforced
particulates. Mg2Si compound is likely to precipitate at the matrix/particle interfaces of 6063/SiC composite.
Keywords: 6063, SiC, clustering, cracking, porosity, clustering
DEVELOPMENT AND EXPERIMENTAL INVESTIGATION OF MECHANICAL AND MICROSTRUCTURAL...AM Publications
This investigation first envisages the development of series of DP microstructures by inter-critical annealing of initial martensitic and initial austenitic microstructures of micro alloyed steel. Subsequently, these together employing a shielded Metal Arc Welding (SMAW) and investigated in order to understand their structure properties relations with the major aim to assess their potential as structural materials for applications in thicker sections. The wide acceptance of DP steel in structural applications will not be appreciable due to insufficient knowledge regarding its weldability under different welding process. Hence the objective of the presence investigation is to study the mechanical properties of the butt-welded dual phase steel by Shielded Metal Arc Welding process for thicker sections.
Effect of Ytterbium Substitution on the Structural and Magnetic Properties of...ijtsrd
A series of ytterbium substituted Zinc ferrites Zn YbxFe1 x 2O4 with x=0.0000, 0.0125, 0.0250, 0.0375, 0.0500 was synthesized by the solid state method. The structural characterizations of all the prepared samples were done by using X ray diffraction XRD . These studies confirmed the formation of single phase structure in all compositions. The increase in the value of lattice parameter with increase in ytterbium concentration suggests the expansion of unit cell. Crystallinity and the crystallite size are observed to increase with the concentration of Ytterbium. The substitution of ytterbium strongly influences the magnetic characteristics and this is confirmed from the magnetization measurements at room temperature. Zar Zar Myint Aung "Effect of Ytterbium Substitution on the Structural and Magnetic Properties of Nanocrystalline Zinc Ferrite" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd27826.pdf Paper URL: https://www.ijtsrd.com/physics/other/27826/effect-of-ytterbium-substitution-on-the-structural-and-magnetic-properties-of-nanocrystalline-zinc-ferrite/zar-zar-myint-aung
Study on Processing and Mechanical Properties of nano SiCp reinforced AA7075theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
Theoretical work submitted to the Journal should be original in its motivation or modeling structure. Empirical analysis should be based on a theoretical framework and should be capable of replication. It is expected that all materials required for replication (including computer programs and data sets) should be available upon request to the authors.
The International Journal of Engineering & Science would take much care in making your article published without much delay with your kind cooperation
— Heat exchangers included in air conditioning systems for aircraft are produced by brazing stamped thin alloys sheets made of nickel-based alloys, Alloy 600 and Ni 201, or stainless steel, AISI 444. Separation metal sheets and locking bars of Alloy 625 are used to complete the system. The brazing filler metal, mainly composed of nickel, manganese, silicon and copper, is referred as BNi-8. In order to control brazing process, a good knowledge of both the brazing filler metal metallurgical behavior and of the interaction with the base metal is essential. The study of the brazing filler metal melting behavior in itself reveals that the melting point is highly dependent on the chemical composition and especially on silicon content. Microstructures analysis showed the presence of several phases with significant differences in terms of mechanical properties at a small scale which could induce local embrittlement. Interactions between the brazing filler metal and the different alloys constitutive of the assembly induce chemical composition evolutions related to the local configuration of the assembly. Dissolution and interdiffusion processes as well as chemical exchanges with the furnace environment occur. Finally, due to this set of phenomena, significant brazing defects can affect the mechanical integrity of the component.
Study on hardening mechanisms in aluminium alloysIJERA Editor
The Al-Zn-Mg alloys are most commonly used age-hardenable aluminium alloys. The hardening mechanism is
further enhanced in addition of Sc. Sc additions to aluminium alloys are more promising. Due to the
heterogeneous distribution of nano-sized Al3Sc precipitates hardening effect can be accelerated. Mainly,
highlight on hardening mechanism in Al-Zn-Mg alloys with Sc effect is to study. In addition, several
characterisations have been done to age-hardening measurements at elevated temperatures from 120oC to 180
oC. The ageing kinetics has also been calculated from Arrhenius equation. Furthermore, friction stir processing
(FSP) can be introduced to surface modification process and hardened the cast aluminium alloys. In this study,
hardening mechanism can be evaluated by Vicker’s hardness measurement and mechanical testing is present
task.
Study on hardening mechanisms in aluminium alloysIJERA Editor
The Al-Zn-Mg alloys are most commonly used age-hardenable aluminium alloys. The hardening mechanism is
further enhanced in addition of Sc. Sc additions to aluminium alloys are more promising. Due to the
heterogeneous distribution of nano-sized Al3Sc precipitates hardening effect can be accelerated. Mainly,
highlight on hardening mechanism in Al-Zn-Mg alloys with Sc effect is to study. In addition, several
characterisations have been done to age-hardening measurements at elevated temperatures from 120oC to 180
oC. The ageing kinetics has also been calculated from Arrhenius equation. Furthermore, friction stir processing
(FSP) can be introduced to surface modification process and hardened the cast aluminium alloys. In this study,
hardening mechanism can be evaluated by Vicker’s hardness measurement and mechanical testing is present
task.
Precipitation and Hetero-nucleation Effect of V( C
1. Vol.23 No.6 LI Xincheng et al: Precipitation and Hetero-nucleation Effect of…844
DOI 10.1007/s11595-007-6844-x
Precipitation and Hetero-nucleation Effect of V(C, N)
in V-Microalloyed Steel
LI Xincheng1
, ZHAO Liangyi1
, WANG Xinyu2
, ZHAO Yutao2
(1.Advanced Forming Technology Institute, Jiangsu University, Zhenjiang 212013,China;
2.School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013,China)
Abstract: The precipitation behavior of V(C, N) in steels microalloyed with vanadium was
researched using a thermal simulator during single-pass deformation at 800-750 ℃. The V(C, N) pre-
cipitates and its nucleation effect on ferrite were investigated by TEM and EDS. The experimental
results show that there are two remarkable heterogeneous nucleation effects of V(C, N) particles pre-
cipitated before γ→αphase change: primary reason is that high coherency between V(C, N) and
ferrite promotes V(C, N) to become a nucleating center of intragranular ferrite; secondary reason is that
the coarsening of V(C, N) causes locally solute-poor region in austenite, thus expedites the nucleation
of intragranular ferrites further. Furthermore, the relationship between the size and shape of V(C, N)
was studied, and identification method was provided for distinguishing interphase precipitation and
general precipitation to avoid erroneous judgment and misguide.
Key words: V(C, N); heterogeneous nucleation; deformation enhanced ferrite transformation
1 Introduction
For a long term, there were few studies on defor-
mation precipitation and heterogeneous nucleation effect
of carbonitrides of microalloy elements in steels[1, 2]
. The
extremely constraints on this study are mainly because
the carbonitride of microalloy elements in steel is negli-
gible, and lack of high-accuracy method to detect the
morph and location of these precipitates. Studies on this
aspect are only about niobium and titanium micoalloyed
steel, so far it is rarely seen a systematic research on the
nucleating effect and grain refining mechanism of V(C, N)
particles in V-microalloyed steel. The present works
indicate that V(C, N) particles have very obvious het-
erogeneous nucleation effect in V-microalloyed steel. In
order to explore the contribution of nucleating effects of
V(C, N) particles to structure refinement as well as its
refining mechanism, it’s necessary to go deep into ob-
servation and analysis on structure pattern and precipita-
tion phases of microalloyed steels.
2 Experimental
2.1 Raw materials
Carbon structural steel Q235 (steel A in table 1) was
used as a contrast steel and the mid-component of Q235
was used as basic ingredient. Microelement vanadium
was added into the steels. The contents of vanadium and
nitride were mainly adjusted. The effect of V(C, N) par-
ticles on intragranulary nucleated ferrites was investi-
gated. Specific chemical compositions are shown in Table 1.
The phase transformation point Ar3 was measured by a
foremaster digital full automatic phase transformation
machine and a metallographic analysis apparatus under
the conditions of holding 5 min at 1200 ℃ with 30%
deformation amount, the heating and cooling rate was
10 ℃/s. Table 1 shows Thermo-Calc calculations of the
equilibrium phase transition point Ae3 in microalloyed
steels with vanadium.
A 25 kg vacuum inductance furnace was used to
smelt the test steels. The ingot was forged into cylinder
specimens. Forging temperature was 1200-950 ℃, and
normalization temperature was 950 ℃. The specimens
were isothermally treated at 950 ℃ for 10 min and then
cooled to room temperature by air. Then it was machined
to form a φ8×12.4 mm compression specimen.
(Received: Nov. 12, 2007; Accepted: May 6 2008)
李李李LI Xincheng( ): Prof.;Ph D;E-mail:lixincheng@ujs.edu.cn
Funded by the National Natural Science Foundation of China (50775102)
and the Universities Natural Science Fund Key Project of Jiangsu Province
(04KJA430021)
2. Journal of Wuhan University of Technology-Mater. Sci. Ed. Dec. 2008 845
2.2 Procedures
Single-pass compression test were proceeded on a
gleeble-2000 thermal simulator. Transformation proc-
esses were as follows. Specimens were austenitized at
1200 ℃ for 5 min to make sufficient solutionizing of
vanadium, followed by cooling at rate of 10 ℃/s and then
deformed throughout undercooled austenite range. De-
formation temperature(T) were 800 ℃(Ae3)-750 ℃(Ar3),
deformation amount(ε) were 30%, 50%, 60% and 70%,
respectively, and the rate of deformation were 50 s
-1
.
The influences of static recovery and recrystallization on
ferrites were eliminated by water quenching to room
temperature immediately after deformation.
Structure detection and analysis schedules are as
follows. Specimens were parted at 1/3 diameter along the
compression axial direction and cor %roded by 2 - %4
nital for investigating the metallographic structure after
thermal simulation deformation. Foils for TEM were
prepared by the twin-jet reduction method at 30 V and
cooled by liquid nitrogen. Twin-jet fluid was composed
of %5 perchloric acid %and 95 carbinol. Complex foils
for TEM were prepared by extraction complex technique.
The ingredients of phases were analyzed by a JEM-2010
UHR. V(C, N) particles and structure components in
microstructure were analyzed by a SISC-IAS8.0 image
analysis software. Specimens for chemical phase analysis
were prepared by electroextraction method. Extract was
composed of 10% KCl and 0.5% citric acid monohydrate.
The temperature of electroextraction was 0-5 ℃ and
current density was 20 mA/cm2
. There were few particles
whose sizes are greater than 100 nm, so the particles less
than 100 nm were regarded as nanaphase. The average
sizes of particles 60% made up of the precipitation were
used as the grain size of nanophase, ensuring that it was
representative.
3 Results and Discussion
3.1 Heterogeneous nucleation effect of
V(C, N) precipitates on IGF
The specimens were analyzed by TEM and the re-
sults discovered that V(C, N) particles contributed a two
ways of heterogeneous nucleation effect before γ→α
transformation. First, high coherency between V(C, N)
and ferrite promoted V(C, N) to become a nucleating
center of intragranular ferrite; second, the coarsening of
V(C, N) caused locally solute-poor region in austenite,
thus expedited the nucleation of intragranular ferrite
further(Fig.1).
Fig.1 (a) shows a polygonal V(C, N) particle pre-
cipitated in austenite grain. An island ferrite formed up-
side it and a complete epitaxial growth ferrite formed at
the bottom plane of the V(C, N) particle. The explanations
is that higher interfacial energy on the pien of particle
make particle grow outside at this position and form a
austenite stable element poor region outside the upper
contour, then form into island ferrite for constitutional
supercooling (this region coincides with the upper con-
tour of the particle). At the bottom of the particle, the
growth of ferrite epitaxially depended on the interface. It
is a representative growth pattern of heteroepitaxy Stran-
ski-Krastanov(S-K)[3]
. For the misfit degree between the
(001) plane of V(C, N) and intragranular ferrite is only
2.0%, high coherency of the lattice decreases specific
Table 1 The Ae3, Ar3 and chemical composition of the test steels(mass fraction, %)
Steel C Si Mn S P V N Ae3/℃ Ar3/℃
A
B
C
0.086
0.091
0.089
0.16
0.18
0.20
0.57
0.56
0.58
0.007
0.005
0.006
0.011
0.0089
0.0094
—
0.064
0.14
0.0032
0.0031
0.0063
862
866
873
718
705
695
Fig.1 Microstructure of quenched C test steel in table 1 with 60% deformation at 800℃
3. Vol.23 No.6 LI Xincheng et al: Precipitation and Hetero-nucleation Effect of…846
surface energy as well as the nucleation free energy, so
V(C, N) become a nucleation center for intragranular
ferrite[4]
. Precipitate in Fig.1(a) has dual grain refining
action, “fragment crystal” action introduced by the
modification of crystallography orientation in austenite
local region upside the particle and hetero-nucleation
effect at the bottom plane of the particle.
Fig.1(b) shows that there exists island structure
which has difference with the ferrite matrix around single
circle V(C, N) particle precipitated in austenite grain, but
the EDS diagram shows that there is Fe peak only (Fig.2).
It is inferred that a special region(island ferrite) is formed
by solute-poor. Crystallography orientation in austenite
local region was changed by island ferrite, and then
caused fragmenting of local austenite. The austenite grain
was fragmented into plenty of subgrains (A in Fig.1(b))
and cellular structure (B in Fig.1(b)), which has the
smallest misorientation. As the proceeding of deforma-
tion, the island ferrites formed continuously in frag-
mented austenite, and thus fragment austenite further.
After that ultra-fine equiaxed grains were obtained.
Fig.2 EDS pattern of island structure
3.2 Formation of “wrapped ferrite”
An experimental phenomenon was observed in
metallographic structure, which has not been reported
before. Some circle, triangular or irregular black patch
structure in ferrites formed in intracrystalline distortion
zone or some granular ferrite were observed. According
to the amplification factor it can be inferred that those
black patch structure have grain sizes less than or equal to
2 μm, which is not precipitates (Fig.3(a)). These parti-
cles were wrapped in ferrite and had clear boundaries
(Fig.3(b)).
Foils that had such feature were analyzed further-
more using TEM and EDS (Fig.4). The results shows that
these small particles wrapped in ferrite grains are also
ferrites using V(C, N) as nucleation center which has
obvious ferrite boundaries. Thus it can be judged that
these black patches are a kind of ferrites which have more
tiny structure than those wrapped outside. These black
patches were called as “wrapped ferrite”.
Fig.3 Microstructure of B test steel in Table 1
(a) Microstructure of granular ferrite
(b) Local zoom in
Fig.4 TEM and EDS images of granular ferrite
3.3 Relation between precipitation shape
and grain size of V(C, N)
Fig.5 shows the shape of V(C, N) particles in C test
steel after 70% compression deformation at 800 ℃. They
were obtained by quenching and holding for different
times. It is indicated that there are few particles with
small sizes, assumed circular or sub-circular before pre-
cipitation (Fig.5(a) and Fig.5(b)). The amount of V(C, N)
particles increases with the increasing of the holding time,
and they distributes uniformly (Fig.5(c)). When the sizes
coarsened to 30 nm, the circles fade-away and changed
into square and sub-square. And then it changed com-
pletely into square and sub-square when the grain al-
ligator was be yond 50 nm (Fig.5(d)). T he explanation
4. Journal of Wuhan University of Technology-Mater. Sci. Ed. Dec. 2008 847
is that there exists a parallel orientation relation between
austenite and the precipitation of microalloy carbonitride
on it[5]
: (100)V(C, N)//(100)γ,(010) V(C, N)//(010).
Dominated by this relation, the effect of interfacial en-
ergy between austenite and V(C, N) particles were very
obvious and misfit degrees were homogenous to each
direction. At present the precipitation of microalloy
carbonitride should be sphere cement out in austenitic
matrix. But interfacial energy will not be leading role
anymore after the growing up of precipitates. Ledges on
interface will be best adherence reaction place for new
diffusion atoms. V(C, N) particles will change into cubic
step wise and show square and sub-square shape under
transmission electron microscope.
For proving whether the precipitates in Fig.5 were
the production of deformation enhanced transformation
during deformation, another three repeated tests were
performed on C test steel in Table 1 with 70% compres-
sion deformation at 800 ℃. The results showed that ag-
ing time of deformation enhanced ferrite transformation
was very short (about 0.025-0.026 s). Moreover, once the
phase transformation occurred, it finished immediately. It
means that precipitates in Fig.5 are certainly the produc-
tion of deformation enhanced transformation during de-
formation.
Fig.6 shows the relation between sizes of V(C, N)
particles and holding time when the C test steel In table 1
was deformed with 70% deformation at 800 ℃. The
particles would grow up when the crystal nucleus was
formed. For microalloy carbonitride nucleated along
dislocation line, diffusion rate of solute atoms along the
dislocation pipeline are faster than atoms on the other
direction. But the segregated solute atoms on dislocation
line have been consumed at the beginning of nucleation.
Oversaturated solute atoms in austenitic matrix during
precipitated growing processes will firstly move to the
dislocation line by lattice diffusion, and then diffuse and
grow up on dislocation line. Lattice diffusion of solute
atom is absolutely a control action in this procedure. This
matches the theory of diffusion control growth.
Fig.6 Relation between size of precipitated phase and holding time
3.4 Effect of deformation amount on pre-
cipitation of V(C, N)
Effect of deformation amount on precipitation of
V(C, N) was examined on specimens austenitized at 1200 ℃
for 5 min followed by air cooling to 750 ℃ with defor-
mation amount(ε) of 0%, 30%, 50% and 70%, respec-
tively. Deformed specimens isothermally treated at 750 ℃
for several seconds. Precipitation mechanism of V(C, N)
at different deformation amounts(ε) was investigated by
TEM and chemical phase analysis method.
The results shows that the precipitation of V(C, N) in
undeformed (ε=0%) austenite is very sluggish. There
was no precipitation of V(C, N) when holding time is less
than 780 s, and ferrite start nucleating on austenite grain
boundary at this time. When holding time was increased
from 780 s to 1560 s, there occurred many V(C, N) par-
ticles successively with sizes of 30-100 nm. This ex-
perimental results indicate that the precipitation of V(C, N)
in undeformed (ε=0%) austenite is very sluggish. It
needs about 13-26 min to finish. Table 2 shows the
measuring result of V(C, N) particles in specimens with
deformation amount (ε) of 30%, 50% and 70% respec-
tively. It is clearly seen from Table 2 that the precipita-
tion of V(C, N) is promoted significantly by deformation
amount. At 750 ℃ with 70% deformation, precipitation
amount of V is 0.063%, about 44.4% of total V-content in
steel.
Fig.5 Microstructure of C test steel in table 1 holding for different times at 800℃ with deformation of 70%
5. Vol.23 No.6 LI Xincheng et al: Precipitation and Hetero-nucleation Effect of…848
3.5 Identification of interphase precipi-
tation and general precipitation
Some tiny spotted second-phase precipitated in the
specimens (volume ratio of ultrafine grain ferrite were
70% and the grain size were 2.8 μm) arranged in align-
ment were observed. These carbonitrides attached on the
interface ofγ→αphase transformation. New precipi-
tated phase was formed row by row by repeated migrat-
ing ofγ→αinterfaces to γ grains, and this is inter-
phase precipitation. Interphase precipitation consists of
irregularly spaced and curved sheets of V(C, N) particles
(Fig.7(a)). This is possibly the pinning of solute particle[6]
in front of migratory phase boundary lead to solute drag,
thus the precipitates had enough time to nucleate. Pre-
cipitates pinned phase boundary efficiently, made the
migration ofγ→αphase boundary blocked, thus lead to
the repeated formation of ordered arrangement and
curved sheets of interphase precipitation. The present
research shows that the similar interphase precipitation
can be observed in the specimens except the contrast steel
(A test steel in Table 1). Another strange phenomenon is
that general precipitation can be observed in different
viewing field in the same specimens (Fig.7(b)). Grain
size of the two kind particles were equal, coinciding with
the conclusion of the Ref.[7]. This leads to derivation of a
more considerable question that interphase precipitation
grains precipitated at higher temperature followsγ→α
phase transformation but general precipitation is the
oversaturated precipitation of ferrite. Grain size of the
two kind precipitates should have obvious difference.
A ledge growth model for ferrite and carbonitride in
interphase precipitation procedure was established to
explain this strange phenomenon (Fig.8). Carbonitride
grains nucleated onγ→αinterface and grown in ferrite.
Ferrite grew up as a ledge pattern in horizontal and ver-
tical orientation. The carbonitride nucleus may be formed
onγ→αinterface after the ferrite grown a wide region
in vertical orientation, and then several narrow ferrite
banding were formed continuously (Fig.9). Microalloyed
carbonitride of interphase precipitation distributed ir-
regularly on planes that once were theγ→αinterface.
Stereoscopic model for transmutation product in inter-
phase precipitation can be shown in Fig.9. Observed from
direction A, precipitated phase grains distributed parallel
onγ→αinterface, but seen from direction B, it distrib-
uted irregularly. For the difference of viewing directions,
interphase precipitation was misidentificated as general
precipitation. As a result, it can be inferred that if the
grain size are equal, they are all interphase precipitation.
So grains in Fig.7(b) are interphase precipitation even
though they look like general precipitation. It should be
emphasized that the description of interphase and general
precipitation in former documents[2,7]
should be carefully
examine and distinguish.
Table 2 Quantitative measuring results of carbonitride
in samples after different deformation
Deforma-
tion tem-
pera-
ture/℃
Defor-
mation
amount
/%
Solution
amount
of V / %
Precipi-
tation
amount
of V/%
Solution
amount/Pre
cipitation
amount
×100%
750
30
50
70
0.117
0.095
0.079
0.025
0.047
0.063
17.6
33.1
44.4
Fig.8 Step growth model for interphase precipitation
Fig.7 Microstructure of C test steel in table 1
with 50% deformation at 760 ℃
6. Journal of Wuhan University of Technology-Mater. Sci. Ed. Dec. 2008 849
Fig.9 Stereoscopic model for interphase precipitation in microalloy
4 Conclusions
a) There were two remarkable heterogeneous nu-
cleation effects of V(C, N) particles precipitated before
γ→α phase change: first, high coherency between V(C,
N) and ferrite promoted V(C, N) to become a nucleating
center of intragranular ferrite; second, the coarsening of
V(C, N) caused locally solute-poor region in austenite,
thus expedited the nucleation of intragranular ferrite
further.
b) The size of precipitated particles had osculating
relations with its form. Grain sizes of sub-circle were
20-30 nm, and square’s and sub-square’s were usually
greater than 50 nm.
c) A step growth model was established for inter-
phase precipitation and general precipitation, and identi-
fication method was suggested for avoid erroneous
judgments and misguide.
References
[1] Yasuya. Microstructural Evolution with Precipitation of
Carbides in Steels[J]. ISIJ International, 2001, 41(6):
554-565
[2] M Sobral, P R Mei, H J Kestenbach. Effect of Carbonitride
particles formed in Austenite on the Strength of Microal-
loyed Steels[J]. Materials Science and Engineering, 2004,
367(2):317-321
[3] X C Li, M Zhang, X J Xu. The Effect of Nanophase on the
Nucleation of Intragranular Ferrite in Microalloyed Steel[J].
Chinese Journal of Mechanical Engineering, 2007(in Chi-
nese)
[4] X C Li, Y F Jiang, S G Cai. The Effect of V, Nb and De-
formation Condition on Deformation Enhanced Transfor-
mation in Microalloying Steel[J]. Transactions of the Chi-
nese Society for Agricultural Machinery, 2007(in Chinese)
[5] D Q Bai, F Hamad, J Asante. Precipitation Strengthening in a
low Carbon Microalloyed Steel[J]. Materials Science Forum,
2005, 4:481-488
[6] Y Li, D N Crowther, T N Baker. The Effects of Vanadium,
Niobium, Titanium and Zirconium on the Microstructure and
Mechanical Properties of Thin Slab Cast Steels[J]. ISIJ In-
ternational, 2004, 44(6):1093-1102
[7] S S Campos, E V Morales, H J Kestenbach. Detection of
Interphase Precipitation in Microalloyed Steels by Micro-
hardness Measurements[J]. Materials Characterization,
2004, (52):379-384