This study investigated the effects of annealing heat treatment on the microstructure and mechanical properties of welded low-carbon steel pipes with 0.078% carbon content. Welding was performed on steel pipe samples, followed by heat treating one of the samples at 850°C for 2 hours. Hardness tests and microstructural analysis were conducted on the heat treated and untreated samples. The results showed that the heat treated sample had a lower hardness and a more predominant pearlite structure compared to the untreated sample. This resulted in improved ductility and toughness for the heat treated sample due to carbon diffusion and grain refinement during annealing. Therefore, annealing heat treatment is recommended after welding low-carbon steel to obtain higher ductility properties.
Since so many years a problem occurs in KSB Pump Va mbori for casting process i.e. cracks occurs in the castings & it is repeated one. Therefore the compan y has given opportunity to me to solve this problem . In case of steel casting there are mainly cracks & also blo w holes induced due to the casting procedure. There are many factors for the casting defects .The factor is unev en material feeding in casting & also due to the mo uld material & also the core material. These cracks finally brea k directly the component of the casting i.e. in cas e of pump the casting component is like Impeller,Volute casing & casing cover. At the time of feeding of steel material in to the casting the material is in liquid us form i.e. it i s hot material & this material is feeding into casting at the time o f feeding it develop different region of heat. At o ne side the temp is high &at other side the temp is low this also pr oduce cracks. To simulate that casting we use the M AGMA SOFTWARE for simulation & validate it using NDT.
EVALUATION OF PROCESSES PARAMETER AND MECHANICAL PROPERTIES IN FRICTION STIR ...IAEME Publication
The present study focuses on Friction Stir Welding of steel being very popular due to the vast application in the fields of automotive and ship building industries. The main constrained of welding steel has considered due to severe loads and temperatures at the interface of FSW tool and parent materials. Ti and pcBN based alloys are suitable for joining steel alloys up to 15 mm thick was found during study. Many researchers carried out study on FSW of steel and found on weld process parameters, mechanical properties, microstructure and the tool employed to produce the weld. It was found that carbon content, welding speed as well as the rotational speed affects between the mechanical properties and the microstructure of the weld.
Investigation of 316L Stainless Steel by Flame Hardening ProcessIJAEMSJORNAL
Austenitic stainless steel offer great imperviousness to general erosion because of the development of a detached surface film. They are broadly utilized as a part of the sustenance and concoction preparing ventures and in addition in biomaterial applications. In any case, they can experience the ill effects of setting erosion in chloride particle containing arrangements. All things considered, in the meantime they have discovered little use in mechanical building applications in view of their low hardness and poor wear resistance. In this examination work, to enhance the previously mentioned reasons, surface solidifying by Flame hardening procedure is done. It has for some time been an outstanding a warm treatment for enhancing the surface properties of austenitic stainless steel. The examples were fire solidified for 5 minutes, 10 minutes and 15 minutes separately. Wear test for every one of the examples were completed by stick on plate testing process. The outcomes were contrasted and an untreated specimen and finished up with metallographic tests like optical tiny tests and examining electron magnifying lens tests.
Effect of Chilling on Soundness, Micro Hardness and Ultimate Tensile Strength...INFOGAIN PUBLICATION
An investigation has been carried out to fabricate and evaluate the strength and soundness of chilled composites consisting of nickel matrix and fused silica particles (size 40–150 μm) in the matrix. The dispersoid added ranged from 3 to 12 wt. % in steps of 3%. The resulting composites cast in moulds containing metallic and non metallic chill blocks (MS, SiC& Cu) were tested for their microstructure, hardness and tensile strength properties. The main objective of the present research is to obtain fine grain Ni/SiO2 chilled sound composite having very good properties. Results of the investigation reveal the following: (1) Strength of the composite developed is highly dependent on the location of the casting from where the test specimens are taken and also on the dispersoid content of the composite. (2) Chill thickness and chill material, however, does significantly affect the strength and soundness of the composite. (3) Soundness of the composite developed is highly dependent on the chilling rate as well as the dispersoid content.
Since so many years a problem occurs in KSB Pump Va mbori for casting process i.e. cracks occurs in the castings & it is repeated one. Therefore the compan y has given opportunity to me to solve this problem . In case of steel casting there are mainly cracks & also blo w holes induced due to the casting procedure. There are many factors for the casting defects .The factor is unev en material feeding in casting & also due to the mo uld material & also the core material. These cracks finally brea k directly the component of the casting i.e. in cas e of pump the casting component is like Impeller,Volute casing & casing cover. At the time of feeding of steel material in to the casting the material is in liquid us form i.e. it i s hot material & this material is feeding into casting at the time o f feeding it develop different region of heat. At o ne side the temp is high &at other side the temp is low this also pr oduce cracks. To simulate that casting we use the M AGMA SOFTWARE for simulation & validate it using NDT.
EVALUATION OF PROCESSES PARAMETER AND MECHANICAL PROPERTIES IN FRICTION STIR ...IAEME Publication
The present study focuses on Friction Stir Welding of steel being very popular due to the vast application in the fields of automotive and ship building industries. The main constrained of welding steel has considered due to severe loads and temperatures at the interface of FSW tool and parent materials. Ti and pcBN based alloys are suitable for joining steel alloys up to 15 mm thick was found during study. Many researchers carried out study on FSW of steel and found on weld process parameters, mechanical properties, microstructure and the tool employed to produce the weld. It was found that carbon content, welding speed as well as the rotational speed affects between the mechanical properties and the microstructure of the weld.
Investigation of 316L Stainless Steel by Flame Hardening ProcessIJAEMSJORNAL
Austenitic stainless steel offer great imperviousness to general erosion because of the development of a detached surface film. They are broadly utilized as a part of the sustenance and concoction preparing ventures and in addition in biomaterial applications. In any case, they can experience the ill effects of setting erosion in chloride particle containing arrangements. All things considered, in the meantime they have discovered little use in mechanical building applications in view of their low hardness and poor wear resistance. In this examination work, to enhance the previously mentioned reasons, surface solidifying by Flame hardening procedure is done. It has for some time been an outstanding a warm treatment for enhancing the surface properties of austenitic stainless steel. The examples were fire solidified for 5 minutes, 10 minutes and 15 minutes separately. Wear test for every one of the examples were completed by stick on plate testing process. The outcomes were contrasted and an untreated specimen and finished up with metallographic tests like optical tiny tests and examining electron magnifying lens tests.
Effect of Chilling on Soundness, Micro Hardness and Ultimate Tensile Strength...INFOGAIN PUBLICATION
An investigation has been carried out to fabricate and evaluate the strength and soundness of chilled composites consisting of nickel matrix and fused silica particles (size 40–150 μm) in the matrix. The dispersoid added ranged from 3 to 12 wt. % in steps of 3%. The resulting composites cast in moulds containing metallic and non metallic chill blocks (MS, SiC& Cu) were tested for their microstructure, hardness and tensile strength properties. The main objective of the present research is to obtain fine grain Ni/SiO2 chilled sound composite having very good properties. Results of the investigation reveal the following: (1) Strength of the composite developed is highly dependent on the location of the casting from where the test specimens are taken and also on the dispersoid content of the composite. (2) Chill thickness and chill material, however, does significantly affect the strength and soundness of the composite. (3) Soundness of the composite developed is highly dependent on the chilling rate as well as the dispersoid content.
Comparison of Mechanical Properties of Austempered, Normalized and As-Weld Ca...IJAEMSJORNAL
More often than not, welded joints experience failure such as fracture which jeopardize their reliability and ergonomics when put in perspective. Attempting a significant improvement in the mechanical properties of welded joint through heat treatment could ensure joints stability and reduce the costs associated with constant repairs and replacements. In this study, the effects of heat treatments (austempering and normalization) on the mechanical properties of weldments were examined. The locally recycled steel sample was sourced from the Delta Steel Company Aladja, Delta State and the spectro-analysis was carried out on it. The test samples were machined as per properties for tests, fractured locally and were welded using shielded metal arc welding (SMAW) with stainless steel electrode. They were then heat treated in electric furnaces. The mechanical properties (tensile strength, yield strength, hardness and impact toughness) were determined and the microstructure examined using scanning electron microscope. They were also examined physically using hand lens. The result indicated that the austempered samples improved significantly in terms of its tensile strength, yield strength, hardness and ductility. It was also found that the untreated sample produced the greatest impact toughness. The result of the physical examination also suggested that heat treatment using oil based quenchant have the potential to inhibit rust at weld joints.
The main objective of this paper is to
determine casting defects generally happening in an
aluminium die casting process and efforts have been
taken to identify the tools which eliminate the casting
defects. In global prospective this study briefs the
application of the various tools that are used in the
industries for improvement of quality in foundry
industry. In our national prospective these tools are not
so popular, hence this study will help us to utilise the
available technology through which the productivity is
enhanced with safe and economical means. The QC
tools were used to analyse the casting condition of the
given pattern with three dimensional simulations for the
result preparation. This work has been carried out to
improve the quality of the pattern which is made with
gravity die casting process and this was achieved
through continuous quality control operation with QC
tools, then it was taken to test in some simulation
software. The latest trend available in casting and
foundry shops are the scientific approach in
optimization of all kind of fields including optimization
of defects in castings. These trends are incorporated in
the analysis of aluminium die casting.
Finite element simulation of hybrid welding process for welding 304 austeniti...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.
Gravity Sand Casting of Metallurgical Bonded Bimetallic Grinding Roll Made of...IJERA Editor
Bimetallic castings are widely used in the mining industries as construction material for crushers which have to perform high abrasive resistance at the outer side and excellent machinability at the inner side. To manufacture bimetallic casting goods cconsecutive centrifugal and gravity casting methods are commonly applied. Centrifugal and consecutive casting come up with geometrical constraints at the parting line of both materials. This research dealed with the manufacturing of tapered grinding roll by applying gravity casting method. The possibilities of casting the white cast iron outer ring in the preheated ductile cast iron of the inner ring were investigated. The inner ring was first heated up by casting liquid metal around the inner side, which prevented the inner ring from cracking due to rapid expansion during the casting process and to provide adequyate shrinkage of inner ring during solidification. After achieving the desired temperature of the inner ring, the liquid metal of white cast iron was then poured into the cavity to form the outer ring. The preheating temperature of the inner ring was mainly derived from the linear thermal expansion of both quasi isotrophic material and the diffusion at the parting line. This preheating temperature has to facilitate the formation of metallurgical bonding and avoid cracks due to the difference of shrinkage value between inner and outer ring. The preheating temperature was set up in the range of 500°C -1000 °C and the flushing time was fixed for 7 seconds. Studies on the microstructure of sample material have revealed a formation of metallurgical bonding at all of the preheating temperature. The width of the diffusion at the interface area varied between 291 µm at 500 oC preheating temperature, 301 µm at 625 oC, 834,8 µm at 750 °C, 909,1 µm at 875 °C and 1027,7 µm at 1000 °C. By preheating temperature of higher than 750°C fusion occured at the interface area between inner and outer material. This research concludes that the casting of bimetallic by applying gravity casting method can be done by preheating the inner ring to 625 oC, interface temperature of 1150 oC, flushing time of 7 seconds and pouring the white cast iron outer ring at the temperature of 1430 oC
Experimental Study with Rotating Tool Electrode of EDM for NiAlloyIJMER
Conventional machining process has the limitation when desired surface finish and
dimensional accuracy in geometry is required in difficult to machine aerospace materials especially for
the cases of drilling holes. Non conventional advance machining processes (AMPs) are extensively used
in the industry to machine for the complex geometrical dimension along with desired surface finish in
hard materials. Electrical Discharge machining with modification for holding and rotating the
electrode has been used in the present experiment for making holes in the Nimonic alloy. This paper
investigate the influence of gap current, pulse on time, duty factor, tool electrode rpm and especially the
polarity of the machine on Material Removal Rate (MRR) and surface roughness (Ra) for machining of
Nimonic alloy. It is observed that with suitable control of input parameters of Electrical Discharge
drilling (EDD), MRR and Ra both found to be improving together from 60 to 90 mg and 4.8 to 2.9 µm
respectively which confirm the viability of using tool electrode rotation in EDM machining.
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.
An investigation of Effect of Mould Vibrations on Mechanical and Metallurgica...journal ijrtem
Abstract: Casting is one of the oldest and mostly used production processes in industry. The traditional casting has certain disadvantages like poor strength due to hot tears, shrinkage and poor surface finish. The property of casting process mostly depends on the microstructure after solidification. Providing Mould vibration during casting is one of the latest techniques employed in order to get better structure in the solidified casting. Mould vibration during casting gives reduced amount of shrinkage, better morphology, surface finish, and less chances of hot tear. In this research work, the effect of mould vibration during solidification of Aluminum 356alloys for different values of wavelengths at a fixed pouring temperature investigated to understand the modification in microstructure and mechanical properties of casting. The Al356 casting has been prepared in a graphite mould with and without vibrations. The frequencies are varied from 0 Hz to 20 Hz during the casting process. A casting has been made without vibration as well to compare the results of castings with vibration. The experimental results showed significant grain refinement and remarkably improvement in compression strength and hardness of castings with mechanical mould vibration during solidification. Key words: Mould Vibrations, Stir casting, Vibrating table, Ultimate tensile strength, hardness and microstructure.
Study on Influence of heat treatment on Tribological properties of mild steeldbpublications
A study was made on the effect of heat treatment upon the mild steel. Total six samples were prepared for each test (hardness test, tensile test, microstructure test and wear test) from those two was tested as received and rest four were subjected to different heat treatment that are annealing and normalizing (heated on a temperature of 850 degree Celsius). The hardness of all sample was measured by Rockwell hardness testing machine. Wear measurement was done on pin-on disc wear machine. Tensometer was used to find out the ultimate stress and strain of the sample. The result of tensile test showed that the strength is decreased by heat treating and the surface hardness is also decreased by heat treatment. Microstructure of the mild steel specimens shows the grain boundary of the particles and the content of % of carbon present. It justifies the experimental results of tensile test and hardness test. Surface Hardness is the measure of resistance that any material applies. As the specimen gets soft on treating the hardness also gets decreased. Tensile strength of any specimen is specified as how much stress the material can withstand before breaking. As the metal gets soft after heat treatment the load required for breaking goes on decreasing. Wear test is carried out to see the variation in wear measurement and coefficient of friction as the mesh size of paper are varied. More soft the surface of material is more wear is seen and vice-versa.
In this work, effect of welding electrode, welding current and corrosion media on
corrosion behaviour of three kinds of stainless steel (AISI 304, AISI 316 and AISI 410)
was investigated. Welding was performed by manual metal arc welding process using
three types of welding electrode (E308L, E316L and E310). Corrosion behaviour of
the welded joints was examined in two chloride mediums (3.5%NaCl and 3.5%KCl).
The results showed that welding electrodes E316L and E310, which contain Mo and
Ni respectively, increase corrosion resistance in of the weldment. The increment in
heat input by increasing welding current caused reduction in corrosion resistance by
facilitating carbon diffusion and formation of chromium carbides in the weld area. It
was also found that corrosion rate of 3.5% NaCl was more aggressive than 3.5% KCl.
Experimental analysis of various pcs by spark testingSumit Dharmarao
Knowledge of material properties, production
methods and manufacturing processes are each
important subject in the material science discipline.
Material testing methods are standardized by several
organizations, such as ASTM, ISO, ASM and DIN etc.
Materials are tested and their mechanical properties
are tabulated in handbooks. This project will explain a
study conducted on how a certain number of carbon
steels might be identified through the observation of
the sparks projected when a specimen is held against a
grinding wheel. There are many factors that can
change the spark patterns that are projected, but the
main goal of this project is to attempt to standardize a
method of spark testing and how it is performed. The
study was conducted on six different grades of carbon
steels that are commonly used in manufacturing
processes. A reference manual was created from the
experimental data cataloguing the spark pictures. This
manual can be used by students and potentially by
machine shops to identify samples of the included
materials. This can lead to significant savings for
machine shops by using a relatively easy, user friendly
method, to identify unknown stock sitting around in
the shop
Effect of Powder Mixed Dielectric Fluid on MRR And SR During Electrical Disch...IJERDJOURNAL
ABSTRACT: This paper mainly focussed to investigate the machining characteristics of RENE 80 Nickel Alloy during powder mixed electrical discharge machining. The experiments were conducted considering electrical parameters (pulse on time, peak current and pulse off time) at optimal combination to get maximum material removal rate by varying powders like aluminium, graphite and combination of aluminium and graphite powders and their concentrations. The experimental results reveal that improvement in material removal rate with addition of powders into dielectric fluid. The maximum material removal rate (75.08 mm3 /min) was noticed with graphite powder substances at 9 g/l. Minimum surface roughness (4.44µm) was noticed at the combination of aluminium and graphite powders (1:1 ratio) substance of 4.5 g/l. However considering simultaneously better values of all two responses namely material removal rate (71.90 mm3 /min) and surface roughness (4.44µm) are obtained with the combination of aluminium and graphite powders (1:1 ratio) of 4.5 g/l.
Effects of Continuous Cooling On Impact and Micro Structural Properties of Lo...IJMER
Some mechanical properties and microstructural analysis were conducted on shielded
metal arc weldments of low carbon steels in some simulated environments. Specimens were prepared
and subjected to welding and continuous cooling at the same time at various positions. Results obtained
for impact strength using Charpy impact testing machine showed that impact strength of water cooled
samples were higher compared to salty water cooled samples. This is due to the increased formation of
martensitic structure and finer pearlite grains. The microstructure of the samples was studied using
photographic visual metallurgical microscope. For low cooling rate as in the air cooled sample, the
austenite was observed to transform into ferrite and pearlite. Ferrite is a body-centred cubic crystal
structure of iron alloys. For higher cooling rates of water and salt water cooled samples, low
temperature transformation products like bainite (an acicular microstructure which is not a phase) or
martensite (a very hard form of steel crystalline structure) were formed. The salt water cooled samples
had more martensite regions because of the increased cooling rate
Reducing Corrosion Rate by Welding DesignIJERD Editor
The paper addresses the importance of welding design to prevent corrosion at steel. Welding is
used to join pipe, profiles at bridges, spindle, and a lot more part of engineering construction. The
problems happened associated with welding are common issues in these fields, especially corrosion.
Corrosion can be reduced with many methods, they are painting, controlling humidity, and also good
welding design. In the research, it can be found that reducing residual stress on the welding can be
solved in corrosion rate reduction problem.
Preheating on 500oC and 600oC give better condition to reduce corosion rate than condition after
preheating 400oC. For all welding groove type, material with 500oC and 600oC preheating after 14 days
corrosion test is 0,5%-0,69% lost. Material with 400oC preheating after 14 days corrosion test is 0,57%-0,76%
lost.
Welding groove also influence corrosion rate. X and V type welding groove give better condition to reduce
corrosion rate than use 1/2V and 1/2 X welding groove. After 14 days corrosion test, the samples with
X welding groove type is 0,5%-0,57% lost. The samples with V welding groove after 14 days corrosion test is
0,51%-0,59% lost. The samples with 1/2V and 1/2X welding groove after 14 days corrosion test is 0,58%-
0,71% lost.
Comparison of Mechanical Properties of Austempered, Normalized and As-Weld Ca...IJAEMSJORNAL
More often than not, welded joints experience failure such as fracture which jeopardize their reliability and ergonomics when put in perspective. Attempting a significant improvement in the mechanical properties of welded joint through heat treatment could ensure joints stability and reduce the costs associated with constant repairs and replacements. In this study, the effects of heat treatments (austempering and normalization) on the mechanical properties of weldments were examined. The locally recycled steel sample was sourced from the Delta Steel Company Aladja, Delta State and the spectro-analysis was carried out on it. The test samples were machined as per properties for tests, fractured locally and were welded using shielded metal arc welding (SMAW) with stainless steel electrode. They were then heat treated in electric furnaces. The mechanical properties (tensile strength, yield strength, hardness and impact toughness) were determined and the microstructure examined using scanning electron microscope. They were also examined physically using hand lens. The result indicated that the austempered samples improved significantly in terms of its tensile strength, yield strength, hardness and ductility. It was also found that the untreated sample produced the greatest impact toughness. The result of the physical examination also suggested that heat treatment using oil based quenchant have the potential to inhibit rust at weld joints.
The main objective of this paper is to
determine casting defects generally happening in an
aluminium die casting process and efforts have been
taken to identify the tools which eliminate the casting
defects. In global prospective this study briefs the
application of the various tools that are used in the
industries for improvement of quality in foundry
industry. In our national prospective these tools are not
so popular, hence this study will help us to utilise the
available technology through which the productivity is
enhanced with safe and economical means. The QC
tools were used to analyse the casting condition of the
given pattern with three dimensional simulations for the
result preparation. This work has been carried out to
improve the quality of the pattern which is made with
gravity die casting process and this was achieved
through continuous quality control operation with QC
tools, then it was taken to test in some simulation
software. The latest trend available in casting and
foundry shops are the scientific approach in
optimization of all kind of fields including optimization
of defects in castings. These trends are incorporated in
the analysis of aluminium die casting.
Finite element simulation of hybrid welding process for welding 304 austeniti...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.
Gravity Sand Casting of Metallurgical Bonded Bimetallic Grinding Roll Made of...IJERA Editor
Bimetallic castings are widely used in the mining industries as construction material for crushers which have to perform high abrasive resistance at the outer side and excellent machinability at the inner side. To manufacture bimetallic casting goods cconsecutive centrifugal and gravity casting methods are commonly applied. Centrifugal and consecutive casting come up with geometrical constraints at the parting line of both materials. This research dealed with the manufacturing of tapered grinding roll by applying gravity casting method. The possibilities of casting the white cast iron outer ring in the preheated ductile cast iron of the inner ring were investigated. The inner ring was first heated up by casting liquid metal around the inner side, which prevented the inner ring from cracking due to rapid expansion during the casting process and to provide adequyate shrinkage of inner ring during solidification. After achieving the desired temperature of the inner ring, the liquid metal of white cast iron was then poured into the cavity to form the outer ring. The preheating temperature of the inner ring was mainly derived from the linear thermal expansion of both quasi isotrophic material and the diffusion at the parting line. This preheating temperature has to facilitate the formation of metallurgical bonding and avoid cracks due to the difference of shrinkage value between inner and outer ring. The preheating temperature was set up in the range of 500°C -1000 °C and the flushing time was fixed for 7 seconds. Studies on the microstructure of sample material have revealed a formation of metallurgical bonding at all of the preheating temperature. The width of the diffusion at the interface area varied between 291 µm at 500 oC preheating temperature, 301 µm at 625 oC, 834,8 µm at 750 °C, 909,1 µm at 875 °C and 1027,7 µm at 1000 °C. By preheating temperature of higher than 750°C fusion occured at the interface area between inner and outer material. This research concludes that the casting of bimetallic by applying gravity casting method can be done by preheating the inner ring to 625 oC, interface temperature of 1150 oC, flushing time of 7 seconds and pouring the white cast iron outer ring at the temperature of 1430 oC
Experimental Study with Rotating Tool Electrode of EDM for NiAlloyIJMER
Conventional machining process has the limitation when desired surface finish and
dimensional accuracy in geometry is required in difficult to machine aerospace materials especially for
the cases of drilling holes. Non conventional advance machining processes (AMPs) are extensively used
in the industry to machine for the complex geometrical dimension along with desired surface finish in
hard materials. Electrical Discharge machining with modification for holding and rotating the
electrode has been used in the present experiment for making holes in the Nimonic alloy. This paper
investigate the influence of gap current, pulse on time, duty factor, tool electrode rpm and especially the
polarity of the machine on Material Removal Rate (MRR) and surface roughness (Ra) for machining of
Nimonic alloy. It is observed that with suitable control of input parameters of Electrical Discharge
drilling (EDD), MRR and Ra both found to be improving together from 60 to 90 mg and 4.8 to 2.9 µm
respectively which confirm the viability of using tool electrode rotation in EDM machining.
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.
An investigation of Effect of Mould Vibrations on Mechanical and Metallurgica...journal ijrtem
Abstract: Casting is one of the oldest and mostly used production processes in industry. The traditional casting has certain disadvantages like poor strength due to hot tears, shrinkage and poor surface finish. The property of casting process mostly depends on the microstructure after solidification. Providing Mould vibration during casting is one of the latest techniques employed in order to get better structure in the solidified casting. Mould vibration during casting gives reduced amount of shrinkage, better morphology, surface finish, and less chances of hot tear. In this research work, the effect of mould vibration during solidification of Aluminum 356alloys for different values of wavelengths at a fixed pouring temperature investigated to understand the modification in microstructure and mechanical properties of casting. The Al356 casting has been prepared in a graphite mould with and without vibrations. The frequencies are varied from 0 Hz to 20 Hz during the casting process. A casting has been made without vibration as well to compare the results of castings with vibration. The experimental results showed significant grain refinement and remarkably improvement in compression strength and hardness of castings with mechanical mould vibration during solidification. Key words: Mould Vibrations, Stir casting, Vibrating table, Ultimate tensile strength, hardness and microstructure.
Study on Influence of heat treatment on Tribological properties of mild steeldbpublications
A study was made on the effect of heat treatment upon the mild steel. Total six samples were prepared for each test (hardness test, tensile test, microstructure test and wear test) from those two was tested as received and rest four were subjected to different heat treatment that are annealing and normalizing (heated on a temperature of 850 degree Celsius). The hardness of all sample was measured by Rockwell hardness testing machine. Wear measurement was done on pin-on disc wear machine. Tensometer was used to find out the ultimate stress and strain of the sample. The result of tensile test showed that the strength is decreased by heat treating and the surface hardness is also decreased by heat treatment. Microstructure of the mild steel specimens shows the grain boundary of the particles and the content of % of carbon present. It justifies the experimental results of tensile test and hardness test. Surface Hardness is the measure of resistance that any material applies. As the specimen gets soft on treating the hardness also gets decreased. Tensile strength of any specimen is specified as how much stress the material can withstand before breaking. As the metal gets soft after heat treatment the load required for breaking goes on decreasing. Wear test is carried out to see the variation in wear measurement and coefficient of friction as the mesh size of paper are varied. More soft the surface of material is more wear is seen and vice-versa.
In this work, effect of welding electrode, welding current and corrosion media on
corrosion behaviour of three kinds of stainless steel (AISI 304, AISI 316 and AISI 410)
was investigated. Welding was performed by manual metal arc welding process using
three types of welding electrode (E308L, E316L and E310). Corrosion behaviour of
the welded joints was examined in two chloride mediums (3.5%NaCl and 3.5%KCl).
The results showed that welding electrodes E316L and E310, which contain Mo and
Ni respectively, increase corrosion resistance in of the weldment. The increment in
heat input by increasing welding current caused reduction in corrosion resistance by
facilitating carbon diffusion and formation of chromium carbides in the weld area. It
was also found that corrosion rate of 3.5% NaCl was more aggressive than 3.5% KCl.
Experimental analysis of various pcs by spark testingSumit Dharmarao
Knowledge of material properties, production
methods and manufacturing processes are each
important subject in the material science discipline.
Material testing methods are standardized by several
organizations, such as ASTM, ISO, ASM and DIN etc.
Materials are tested and their mechanical properties
are tabulated in handbooks. This project will explain a
study conducted on how a certain number of carbon
steels might be identified through the observation of
the sparks projected when a specimen is held against a
grinding wheel. There are many factors that can
change the spark patterns that are projected, but the
main goal of this project is to attempt to standardize a
method of spark testing and how it is performed. The
study was conducted on six different grades of carbon
steels that are commonly used in manufacturing
processes. A reference manual was created from the
experimental data cataloguing the spark pictures. This
manual can be used by students and potentially by
machine shops to identify samples of the included
materials. This can lead to significant savings for
machine shops by using a relatively easy, user friendly
method, to identify unknown stock sitting around in
the shop
Effect of Powder Mixed Dielectric Fluid on MRR And SR During Electrical Disch...IJERDJOURNAL
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International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
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Study of effects of heat treatment on the hardness and microstructure of welded low carbon steel pipes
1. Innovative Systems Design and Engineering www.iiste.org
ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online)
Vol.4, No.9, 2013-Special Issue - 2nd International Conference on Engineering and Technology Research
48
Co-published with the Faculty of Engineering and Technology of Ladoke, Akintola University of Technology, Ogbomoso-Nigeria
Study of effects of Heat treatment on the Hardness and
Microstructure of Welded Low Carbon Steel Pipes
L.O. Mudashiru*1
and T.A. Adio2
1. Mechanical Engineering Department, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
2. Mechanical Engineering Department, The Polytechnic Ibadan, Ibadan, Nigeria.
* E-mail of the corresponding author: lomudashiru@lautech.edu.ng
ABSTRACT
This paper reports investigations made on the effects of annealing heat treatment on the micro-structural and
mechanical property behavior of 0.078wt % C steel weld. Welding operation was carried out on the low carbon
steel of 0.078wt % carbon content in pair; followed by heat treating (annealing), the specimen was heat treated at
the weld zone to a temperature of 850°C using digital heat treatment furnace. For effective study of the effect of
annealing on the welded joint, mechanical test (hardness) was carried out and micrographs were obtained to
reveal the microstructures of the heat treated (annealed) and un-heat treated samples. From the micro-structural
analysis, the micrographs shows that the heat treated sample had a more predominant pearlite structure which is
the reason larger areas of the structure is darker and less ferrite structure due to recrystallization and carbon
diffusion; hence a significant improvement in ductility, toughness and grain refinement accompanied with
decrease in hardness and brittleness.
Keywords: Annealing, Ductility, Hardness, Heat treatment, Microstructure, Welding
1. Introduction
One of the most important methods of permanent fastening and versatile means of fabrication available to
industry is welding. This is because it is one of the most important tools available to engineers in his efforts to
reduce production, fabrication and maintenance costs (Adedayo et al., 2010).
Welding is simply an art of joining metals by heating and then pressing together which simply requires a heat
source to produce a high temperature zone to melt the material (though it is possible to weld two metal pieces
without much increase in temperature), its application includes: used in ships building, bridges, pressure vessels,
industrial machinery, automobile, rolling stock and many other fields. Hence the optimization of the welding
process is of the essence in fabrication as its importance cannot be overemphasized but it requires a good
understanding of the microstructures generated by the rapid temperature rise in the heat-affected zone (Bipin et
al., 2010; Kumaar, 2010 and Maamar, 2008).
However with its importance, problems associated with welding are common issues in these fields, as a complex
mixture of two or more constituents is formed when steel or any metal is welded altering its microstructure
(International Institute of Welding Guidelines, 1988) .This complex microstructure mixture can lead to highly
varied properties of the weld or defects (since the properties of steels or metals are related to its structural make-
up (Rajan, 1988). Weld defects may include: cracking, hardness reduction, reduction in strength, distortion, wear
properties, corrosion characteristics, internal stresses and etcetera. These defects cannot be overlooked, as a
means to control them is of essence to an effective design (Khan and Haasen, 1996).
These defects can however be reduced through various types of heat treatment to obtain the desired properties,
simply because a way to unify the structure of the welds is by heat treatment. The science of heat treatment deals
with the control of the constituents in metal by heating and cooling, it also deals with the relationship between
these constituents and the properties of the metal which can be monitored by microscopic examination known as
metallographic. Engineering materials, mostly steel, are heat treated under controlled sequence of heating and
cooling to alter their physical and mechanical properties to meet desired engineering applications (Fadare et al.,
2011).
Previous research on annealing heat treatment effects on steel welds, were carried on samples of varying carbon
content; the results show that hardness and toughness were dependent on the carbon content of the steel
(Adedayo et al., 2010). In this project, special attention was focused on the effect of annealing on the mechanical
and micro-structural properties of welded low steel pipe of 0.078%wt C in other to appropriately adapt it for
better utilization in the aforementioned area of applications of welding.
2. Materials and Method
The specimen used is a low carbon steel pipe (Φ32mm, 2mm thick and 600mm long), which was obtained from
a local market known as “Owode Onirin” market, Lagos state, Nigeria. Chemical composition analysis was
carried out at Universal Steel Rolling Mill, Ogba-Ikeja, Lagos state, Nigeria using the mass analyzer.
2. Innovative Systems Design and Engineering www.iiste.org
ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online)
Vol.4, No.9, 2013-Special Issue - 2nd International Conference on Engineering and Technology Research
49
Co-published with the Faculty of Engineering and Technology of Ladoke, Akintola University of Technology, Ogbomoso-Nigeria
2.1 Equipment
The equipment used for this research are; mass analyzer, digital heat treatment furnace, metallurgical microscope
with in-built camera, electrical arc welding machine, Grinding and polishing machine, hack saw, TECO micro-
hardness tester and welding electrodes.
2.2 Welding Procedure
The specimen was cut into four pieces of equal sizes (150mm long) and welded together in pair. The specimen
(low carbon steel) was welded using electric arc welding at Federal Industrial Institute of Research, Oshodi,
Lagos state, with procedural steps as follows:
i. Clamping of the specimen firmly on the vice.
ii. Welding operation parameters; welding current= 140A; welding voltage=80V; Electrode
specification= 2.5mm (gauge 10)
iii. Welding was carried out at a slow speed.
2.3 Heat Treatment
The heat treatment process (annealing) was carried out at Federal Industrial Institute of Research (FIIRO),
Oshodi, Lagos state Nigeria. A Digital heat treatment furnace with a maximum temperature of 1200°C was used
for the heat treating processes. The specimen was heated at the weld centre line gradually to a temperature of
about 850°C, and then was held for about two hours at this temperature before allowed to cool in the furnace for
24hrs.
2.4 Hardness test
Hardness values of the treated and untreated weld sample was determined using LECO micro-hardness tester;
model: LM-700AT with test load of 490.3MN and a dwell time of 10secs. The LECO micro-hardness tester
automatically calculates the hardness values in Vickers hardness number (VHN). This test was carried out at
Engineering Material and Development Institute (EMDI), Akure, Ondo state Nigeria.
The hardness of the heat treated and untreated welded steel were evaluated at two points: (i) the weld pool region
(ii) the heat affected zone (HAZ).
2.5 Micro-structural Test
The micro-structural examination was carried out as follows; sectioning, grinding, polishing, etching and
microscopic viewing at the Metallurgical department of the University of Lagos, using a metallurgical
microscope.
• Preparation (Sectioning)
Sectioning was carried out by sawing at the weld bead, but care was taken to ensure that the original condition of
the material is not altered.
• Grinding
A silicon carbide paper was used. This strip of paper was laid flat on the heat-treated pipe and the specimen is
robbed to and fro on the strips. Starting with the roughest cloth (240 grit), rub continued until all traces of
cuts/roughness are removed. Turning through 90° and rubbing on the next (finer) paper (320 grit) until the
previous scratches was removed.
• Mechanical Polishing
This was done in two stages with a coarse abrasive agent and fine polishing agent respectively. The specimen
was held against a horizontal rotating wheel covered with a short - pile cloth fed with a suspension cream of the
polishing agent.
• Etching
In this, the specimen was submerged in and swabbed with a chemical reagent (mixture of acid and alcohol) that
removes the surface layer produced on polishing.
• Microscopic Viewing
The sample was illuminated by a reflected light which was mounted on the microscope; the specimen was
viewed through the eyepiece of the microscope so as to determine the micro-structure which was subsequently
by snapped by the attached camera to obtain the micrograph.
3. Results and Discussion
3.1 Spectrometry Result
The result of the chemical composition analysis carried on the low carbon steel sample is shown in table 1.
Table 1: Chemical composition of low alloy steel specimen
Element C Si Mn P S Cr Ni Cu Al Fe
Weight % 0.078 0.025 0.304 0.0049 0.021 0.017 0.031 0.008 0.015 99.4
3.2 Hardness Result
The hardness result obtained from the tests carried out on the heat treated specimen and un-treated specimen of
the low carbon steel pipe were recorded in table 2.
3. Innovative Systems Design and Engineering www.iiste.org
ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online)
Vol.4, No.9, 2013-Special Issue - 2nd International Conference on Engineering and Technology Research
50
Co-published with the Faculty of Engineering and Technology of Ladoke, Akintola University of Technology, Ogbomoso-Nigeria
Table 2: Vickers Hardness test values for annealed and untreated samples
Weld Pool Heat Affected Zone
Annealed 319.7 191.9
Untreated 358.0 202.3
3.3 Micro-structural analysis results
Plate 1 shows the untreated specimen at the weld pool while Plate 2 shows the treated specimen at the weld pool.
Plate 1: Micrograph of untreated specimen weld pool X200
Plate 2: Micrograph of treated specimen weld pool X200
3.4 Discussion of hardness results
From the hardness test results tabulated above, it can be deducted that the annealed specimen hardness is less
than the un-treated specimen and this is due to the recrystallization of the ferrite structure thereby leading to a
reduction in carbon (due to diffusion) content hence increasing the ductility and reducing the hardness.
It is obvious from Table 2 that the hardness values have increased from the heat affected zone (HAZ) to the weld
pool where the hardness is higher; this is due to the carbon content of the electrode which is added during
welding and solid state diffusion of carbon from the base metal; the higher the carbon diluted or diffused into the
weld pool, the higher the hardness values.
3.5 Discussion of micro-structural results
(i) Untreated Specimen
The value for the untreated weld sample is maximum for hardness; this is due to a more predominant ferrite
structure which is the reason considerable area of the structure is white (the higher the carbon diluted and/or
diffused into the weld zone, the higher the hardness values.) as seen in Plate 1.
The arc welding process also induces residual stresses in the weld during the course of welding; the electrodes
have low carbon content which also adds to the original carbon content of the material thereby increasing
hardness and reducing ductility.
(ii) Annealed Specimen
Annealing the specimen, results in the transformation of austenite grains into ferrite and pearlite. The
microstructure observed, shows a coarse grain of ferrite and a coarse structure of pearlite as a result of the
furnace cooling which imparts ductility on the material.
The value for the annealed sample is minimal for hardness and maximum for toughness. This is due to the
softening effects of the ferrite matrix which arise from liberation of trapped carbon atoms in the saturated ferrite
during annealing as depicted in microstructure of the annealed samples in Plate 2. Leading to a more
predominant pearlite structure which is the reason larger areas of the structure is darker hence reducing hardness
and increasing toughness and ductility.
Also, apart from straining due to saturation by carbon atoms which are relieved, residual stresses in the welds are
4. Innovative Systems Design and Engineering www.iiste.org
ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online)
Vol.4, No.9, 2013-Special Issue - 2nd International Conference on Engineering and Technology Research
51
Co-published with the Faculty of Engineering and Technology of Ladoke, Akintola University of Technology, Ogbomoso-Nigeria
also relieved during annealing. Normally, arc welding process can induce residual stresses in the weld during the
course of welding; the electrodes have low carbon content. The higher the carbon diluted and/or diffused into the
weld zone, the higher the hardness values. The weld structure having a low carbon content due to
recrystallization have changed from a harder to a more ability to machine the material by improving the ductility
of the material hence reducing the internal stresses.
4. Conclusion
Mechanical property of ductility and toughness in the annealed weld was found to be higher than the un-
annealed weld specimen due to carbon diffusion and re-crystallization from the weld zone during annealing
accompanied with a refined grain structure. This treatment is recommended as final treatment after welding of
low carbon steel when high ductility is required at the expense of hardness as a pointer to the material
performing creditably well in service.
REFERENCES
Adedayo A.V., Ibitoye S.A. & Oyetoyan O.A. (2010), “Annealing Heat Treatment Effects on Steel Welds”.
Journal of Minerals & Materials Characterization & Engineering, 9(6), 547-557.
Bipin, K. S., Tewari, S. P. & Jyoti, P. (2010), “A Review on Effects of Preheating and/or Post Weld Heat
Treatment (PWHT) on Mechanical Behavior of Ferrous Metals”. International Journal of Engineering Science
and Technology, 2(4), 625-626.
David, Hart (1999). Welding and Coating Metallurgy 2. Published in Austalia, 6-7, 12.
Fadare, D. A., Fadara, T. G. & Akanbi, O. Y. (2011), “Effect of Heat Treatment on Mechanical Properties and
Microstructure of NST 37-2 Steel”. Journal of Minerals & Materials Characterization & Engineering, 10(.3),
299-308.
International Institute of Welding Guidelines (1988). For the Classification of Ferrite Steel Weld Metal
Microstructure Constituents Using the Light Microscopy: International Institute of Welding, IIW DOC. IX-
1533-88.
Kahn Robert & Haasen Peter (1996). Physical Metallurgy. 4th Edition, Holland.
Kumar, Ashish B. (2010). Manufacturing Processes 2; Welding. Kanna Publishers, Unit 5, pp. 43, 49, 50, 55, 60.
Maamar, R. H., Otmani, T. R., & Fahssi, N. D. D., (2008) “Heat Treatment and Welding Effects on Mechanical
Properties and Microstructure Evolution of 2024 and 7075 Aluminium Alloys”. Centre de Recherche
Scientifique et Technique en Soudage et Contrôle. Division de Mécanique et Métallurgie, Algeria. 5, 13-15.
Rajan, T.V., Sharma C.P., & Sharma A. (1988). Heat Treatment Principles and Techniques. Prentice-Hall of
India, Private Ltd. New Delhi.
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