Final strip and sheet steel product is commonly inspected with great scrutiny to qualify material for high-end product requirements. Surface flaws such as slivers, cracks, laps, etc., disqualify these materials from being used in automotive and big box applications. Internal defects such as voids, cracks, laminations, porosity and segregation may remain undetectable with surface inspection methods as they have not yet manifested at the surface. These internal defects often propagate to the surface where ultimately they are detectable in the finished product stage in the form of slivers, blisters, etc., although remaining undetectable in the steel making, hot-rolling, pickling, cold rolling and subsequent finishing operations. Surface flaws are a key cause of down grading of finished product and a significant cost to the steel maker as all value added operations are complete before detection and down grading are possible.
In today’s competitive environment, it is key to maximize utilization of mill assets and to avoid adding value to material which can be known early in the manufacturing process to contain deleterious defects. Using proven methods of volumetric material inspection in two separate case studies, methods have been developed to allow the steel maker to identify poor material early in the process thus avoiding the value added processes on these materials and only processing materials which with a probability of final inspection passage.
1.1 The aim of the experiment
The aim of the experiment is to test the usefulness of the ultrasonic waves, by passing them through different
solids one can find out a lot of physical properties like young’s modulus , defects, Poisson ratio, Velocity of
sound in respective material this is due to the response of the received ultrasonic waves.
1.2 Theory of experiment
Ultrasonic testing (UT) is a family of non-destructive testing (NDT) techniques based on the propagation of ultrasonic waves in the object or material tested. In most common UT applications, very short ultrasonic pulse-waves with center frequencies ranging from 0.1-15 MHz, and occasionally up to 50 MHz, are transmitted into materials to detect internal flaws or to characterize materials. A common example is ultrasonic thickness measurement, which tests the thickness of the test object, for example, to monitor pipework corrosion.
Ultrasonic testing is often performed on steel and other metals and alloys, though it can also be used on concrete, wood and composites, albeit with less resolution. It is used in many industries including steel and aluminium construction, metallurgy, manufacturing, aerospace, automotive and other transportation sectors.
Scope of NDT testing in industries.Details about power plant inspection,rope inspection,storage tank inspection,future scope of NDT,Aircraft inspection,history of NDT,Industrial Area,conclusion
Phased Array Ultrasonic Testing (PAUT) is an advanced method of ultrasonic testing that has applications in medical imaging and industrial nondestructive testing. Common applications are to non-invasively examine the heart or to find flaws in manufactured materials such as welds.
Nondestructive Testing (NDT) has evolved from being a “necessary evil” to being an essential source of competitive advantage. The right technique not only helps control the quality of the final product, but also provides valuable process control feedback to improve productivity, reduce cost, and increase the
efficiency of the welder. This is especially important in high-volume, continuous processing lines where a few minutes of bad production can result in significant losses.
In the last decade, powerful Ultrasonic EMAT technology has come of age with tremendous success, becoming the technique of choice for many applications.
1.1 The aim of the experiment
The aim of the experiment is to test the usefulness of the ultrasonic waves, by passing them through different
solids one can find out a lot of physical properties like young’s modulus , defects, Poisson ratio, Velocity of
sound in respective material this is due to the response of the received ultrasonic waves.
1.2 Theory of experiment
Ultrasonic testing (UT) is a family of non-destructive testing (NDT) techniques based on the propagation of ultrasonic waves in the object or material tested. In most common UT applications, very short ultrasonic pulse-waves with center frequencies ranging from 0.1-15 MHz, and occasionally up to 50 MHz, are transmitted into materials to detect internal flaws or to characterize materials. A common example is ultrasonic thickness measurement, which tests the thickness of the test object, for example, to monitor pipework corrosion.
Ultrasonic testing is often performed on steel and other metals and alloys, though it can also be used on concrete, wood and composites, albeit with less resolution. It is used in many industries including steel and aluminium construction, metallurgy, manufacturing, aerospace, automotive and other transportation sectors.
Scope of NDT testing in industries.Details about power plant inspection,rope inspection,storage tank inspection,future scope of NDT,Aircraft inspection,history of NDT,Industrial Area,conclusion
Phased Array Ultrasonic Testing (PAUT) is an advanced method of ultrasonic testing that has applications in medical imaging and industrial nondestructive testing. Common applications are to non-invasively examine the heart or to find flaws in manufactured materials such as welds.
Nondestructive Testing (NDT) has evolved from being a “necessary evil” to being an essential source of competitive advantage. The right technique not only helps control the quality of the final product, but also provides valuable process control feedback to improve productivity, reduce cost, and increase the
efficiency of the welder. This is especially important in high-volume, continuous processing lines where a few minutes of bad production can result in significant losses.
In the last decade, powerful Ultrasonic EMAT technology has come of age with tremendous success, becoming the technique of choice for many applications.
The field of Non Destructive Testing (NDT) has shown tremendous growth in the last half century. Its ability to provide safe volumetric inspection of materials with limited access areas makes ultrasonic testing (UT) one of the fastest growing technique in NDT.
However, the Achilles heel of Ultrasonic Testing (UT) has always been the transferring of energy from the UT probe into the material subject of the inspection. Because air limits the transfer of ultrasound, the transducers need to be coupled to the material using a liquid that promotes the transfer of energy into the material.
While research and development of Electro-Magnetic Acoustic Transducer (EMAT) technology has been active for several decades, hardened production inspection system applications remain limited. Applications remain limited despite the several and distinct advantages and EMAT probe can have over conventional piezoelectric ultrasonic devices.
In addition to being comparable in ultrasonic wave mode generation and sensitivity, under proper design, an EMAT probe offers the following advantages for the production minded engineer: (1) no fluid couplant is required, (2) the test can be non-contact, (3) works on rough, dirty, and hot surfaces, (4) can be operated at very high scan rates, (5) easy to automate, and (6) capable of generating useful waves modes that are difficult to generate with piezoelectric devices. Basic elements of an EMAT system are explained and a comparison to conventional piezoelectric devices is made. By using real application cases, the benefits of EMATs are demonstrated. These real cases include: (1) flash butt-weld inspection, (2) mill roll inspection, (3) automotive laser weld inspection, and (4) tube & pipe inspection.
Advance NDT method are much efficient than conventional NDT methods. these methods have great amount of automation which help in understanding and comparing the data occupied by different reading. These data can be used for the future references and can be saved and stored. these Advance NDT method can test or inspect any shape such as complex shape very easily and effeciently.
Electromagnetic Acoustic Transducer (EMAT) systems are no longer limited to laboratory applications. With the help of new electronics and software they are now widely used in industrial settings and inservice operations.
Acoustic Emission (AE) refers to the generation of transient elastic waves produced by a sudden redistribution of stress in a material. When a structure is subjected to an external stimulus (change in pressure, load, or temperature), localized sources trigger the release of energy, in the form of stress waves, which propagate to the surface and are recorded by sensors. With the right equipment and setup, motions on the order of picometers (10 -12 m) can be identified. Sources of AE vary from natural events like earthquakes and rockbursts to the initiation and growth of cracks, slip and dislocation movements, melting, twinning, and phase transformations in metals. In composites, matrix cracking and fiber breakage and debonding contribute to acoustic emissions. AE’s have also been measured and recorded in polymers, wood, and concrete, among other materials.
Smart Sound Processing for Defect Sizing in Pipelines Using EMAT Actuator Bas...Innerspec Technologies
Pipeline inspection is a topic of particular interest to the companies. Especially important is the defect sizing, which allows them to avoid subsequent costly repairs in their equipment. A solution for this issue is using ultrasonic waves sensed through Electro-Magnetic Acoustic Transducer (EMAT)
actuators. The main advantage of this technology is the absence of the need to have direct contact with the surface of the material under investigation, which must be a conductive one. Specifically interesting is the meander-line-coil based Lamb wave generation, since the directivity of the waves allows a study based in the circumferential wrap-around received signal. However, the variety of defect sizes changes the behavior of the signal when it passes through the pipeline. Because of that, it is necessary to apply advanced techniques based on Smart Sound Processing (SSP). These methods involve extracting useful information from the signals sensed with EMAT at different frequencies to obtain nonlinear estimations of the depth of the defect, and to select the features that better estimate the profile of the pipeline. The proposed technique has been tested using both simulated and real signals in steel pipelines, obtaining good results in terms of Root Mean Square Error (RMSE).
Guided Wave Ultrasound - Principles and Apllicationssubash_j
This presentation provides a general background on the principles and theory of guided wave ultrasound and its application to inspection of a wide range of structures and materials
Enhancement in NDT inspection for operational effectiveness, efficiency and e...Innerspec Technologies
We intend to show that any change shall be linked, not only to improvement, but also to immediate cost reduction so that all management structure can conceive quick implementation as
part of its department strategy & enhancement in their budget cost.
For that, concepts such as effectiveness, efficiency and excellence must be approached. We will give clear saving cost ways which will follow the terminology.
In Financial terms and without a deep analysis, we can conrm cost savings above 30% from current prices are achieved.
In last meeting in Davos (Switzerland) in January, the World Economic Forum, expressed its decision to expand investments in green energy. Many new projects are going to be present in the next years.
It is expected a erce competition among companies to be awarded with contracts that will secure their businesses. Some companies have been leading the renewable market for years and they have built a substantial moat which place them in an invaluable position in the market. However, though a good start point, it is not unwavering.
It is time for them to start looking forward and push everyone around to join the industry trend 4.0 also enforced by the Forum. Moving in the right direction will end the controversy of Quality Vs. Production which has dragged down many projects damaging company's image.
Application of conventional NDT methods to supervise the quality has been burdening progress. Production department has been reticent to implement advanced NDT techniques based on wrong concepts.
It is time for NDT companies to look at the industry in the right way, showing that there is a way to work for all. Just by moving forward.
In the next lines, we will try to show and explain that NDT industry must lead the progress introducing FEA analysis in their reports if they want to join all stakeholders around project success.
In the fall of 2002, Innerspec introduced and patented an Ultrasonic Testing (UT) inspection system for surface inspection of mill rolls. This novel approach was designed to overcome known limitations of Eddy Current (EC) systems.
In 2014, Whemco Steel Castings Inc., a leader in mill roll manufacturing and service, approached Innerspec Technologies to expand the original Rollmate design with more capabilities.
When challenged to develop a new generation of mill roll inspection systems, Innerspec embraced the task and sought to design a comprehensive solution using the best NDT techniques available for the task.
The system is fully designed and manufactured in the United States, and serviced and supported by Innerspec offices in the US, Mexico, Europe and China.
The objective of this paper is to study how the selection of the coil and the frequency affects the received modes in
guided Lamb waves, with the objective of analyzing the best configuration for determining the depth of a given
defect in a metallic pipe with the minimum error. Studies of the size of the damages with all the extracted
parameters are then used to propose estimators of the residual thickness, considering amplitude and phase
information in one or several modes. Results demonstrate the suitability of the proposal, improving the estimation of
the residual thickness when two simultaneous modes are used, as well as the range of possibilities that the coil and
frequency selection offers.
Sistema de inspección híbrido EMAT-Visión para optimar el proceso de fabricac...Innerspec Technologies
Uno de los principales retos a los que se enfrenta la industria del automóvil es la reducción del peso de partes estructurales, sin que esto afecte a la seguridad del producto final. La fabricación de Tailor Welded Blanks (TWB) en la industria del automóvil es un proceso avanzado que consiste en combinar varias chapas finas de metal que son soldadas mediante tecnología láser antes del proceso de estampado. Aunque la inspección de TWB suele llevarse a cabo mediante la tecnología EMAT, ésta presenta ciertas limitaciones a la hora de identificar defectos superficiales tales como el desalineamiento lateral y vertical de una chapa respecto a otra. Con el fin de
afrontar esta limitación, los fabricantes inspeccionan las chapas con un equipo adicional de visión artificial que complementa los resultados del equipo EMAT. Este artículo presenta el nuevo sistema de inspección OPTIBLANKS, que es el primer equipo híbrido que combina EMAT y visión artificial para establecer un criterio de aceptación/rechazo unificado a través de la combinación de la información proporcionada por ambas tecnologías no destructivas. Esta hibridación dota al sistema final de más inteligencia, lo que le permite tomar decisiones más robustas y optimizar el proceso de fabricación y la calidad del producto final. El artículo presenta los resultados del proceso de validación de OPTIBLANKS en una planta de fabricación de TWB (Gestamp Solblank). Los resultados muestran la necesidad de combinar la información de las dos técnicas para incrementar la probabilidad de detección (POD) del sistema de inspección.
Detección de delaminaciones y otros defectos de unión en productos de acero m...Innerspec Technologies
Ondas guiadas superficiales (Rayleigh) y tipo Lamb fueron usadas para la detección de delaminaciones, residuos de acero embebidos en la matriz del material y problemas de adherencia de la frágil capa intermetálica de Al-Fe en la interfaz formada por el aluminio revestido y el acero generados durante el
proceso de laminación en frío “Cold Roll Bonding” (CRB). Se fabricaron muestras multicapa con defectos artificiales de distintos tamaños, localizados entre el aluminio recubierto y el acero. El objetivo de este manuscrito es mostrar la sensibilidad de las ondas guiadas EMAT para indicar cualitativamente
la presencia de defectos, utilizando para ello técnicas de atenuación de la señal adquirida. Para la generación y recepción de las ondas guiadas se usaron transductores acústico-electromagnéticos (EMAT) dispuestos en configuración pitch-catch (transmisión-recepción). La toma de medidas se llevó a cabo en el material laminado antes y después de aplicar el recocido, de forma que se pudieran evaluar las diferencias que el tratamiento térmico provocaba en términos de atenuación y de relación señal-ruido (SNR). El modo S0 de onda Lamb se demostró adecuado para la detección de delaminaciones y residuos de acero embebidos en la matriz
del material, existiendo una relación entre el grado
de atenuación y, el tipo y tamaño de defecto, así
como con la realización del recocido. Sin embargo
dicho modo no pudo detectar falta de adherencia
de la frágil capa intermetálica de Al-Fe debido a los
espesores de la capa de aluminio recubierto y del
acero. Secciones de las muestras inspeccionadas
con EMAT fueron posteriormente evaluadas metalográficamente para corroborar las indicaciones de
defecto. Los resultados demostraron la viabilidad del uso de ondas guiadas Rayleigh y Lamb para la detección de defectos de unión en la producción en serie de planchas bimetálicas de Al-Sn/Acero.
The United States consumes an incredible amount of energy every day, and this demand for energy shows no signs of decreasing. The U.S. pipeline infrastructure is critical to supporting this growing demand. We take a look at this infrastructure and break down some of the facts including age, material, miles and production.
To learn more about energy production in the U.S. visit the U.S. Energy Information Administration or contact one of our oil & gas sales engineers.
Austenitic welds are extensively used in nuclear, petrochemical and process industries. Due to the strong material anisotropy and coarse grain size in the dendritic weld zone, they are difficult to inspect with ultrasound. In this regard, the shear horizontal (SH) wave mode is far superior to the more conventional shear vertical (SV) and longitudinal wave modes. In this paper, an electromagnetic acoustic transducer (EMAT) is designed and used for the inspection of two austenitic weld samples. Despite the low efficiency of EMAT generation due to low conductivity of austenitic stainless steel material and strong attenuation in the weld zone, good signal to noise ratio is achieved with optimized EMAT probes and state-of-the-art instrumentation. The angle beam EMAT probe successfully detected all defects in the samples with good signal to noise ratio including a 2% defect.
The capability of detection a defect across a 2’’ inch thick and 2’’ wide austenitic weld zone is also demonstrated in the paper.
Electric Resistance Weld (ERW) tubes and pipes are extensively used un many applications including Oil Country Tubular Goods (OCTG) and high quality structures. Efficient in-line nondestructive testing techniques are needed to ensure that the weld quality meets applications standards.
In the fall of 2002, a revolutionary method by which to inspect mill rolls was introduced to the metal producing industry. This ultrasonic approach was designed to overcome the inadequacies of existing inspection techniques while
maximising return on investment. Since then, a number of improvements have been made, and with input from many
roll shops, the latest technologies provide the most comprehensive tool available for the inspection of all types of mill rolls. This paper provides an overview of mill roll
inspection technology and the effects that various inspection technologies can have on the efficiency and costs associated with operating a roll shop. It will also highlight how new techniques provide alternatives otherwise not available.
Clad metals are composite metal containing two or more layers that have been bonded together. The bonding may have been accomplished by rolling, extrusion, welding, diffusion bonding, casting, heavy chemical deposition, or heavy electroplating. Clad metals offer the opportunity to combine desirable properties and/or characteristics of individual metals and alloys into a material "system" that provides improved characteristics over the individual metals. In the event the bond quality is compromised, these materials will not meet their original purpose. Disbond in clad layers is very similar to an internal void in single layer materials such as steel strip material.
Clad metals are multilayered metals containing two or more layers that have been bonded together. This bonding can be accomplished by cold or hot rolling, extrusion, welding, diffusion bonding, casting, heavy chemical deposition, or heavy electroplating.
This paper introduces a new application of guided wave electromagnetic acoustic transducers (EMATs) for the detection of delamination in a brass/copper/brass three-layered composite used for coin stock. In addition to detection, using finite element analysis and guided wave modal analysis, it was possible to model and explain the results for different discontinuity sizes and geometries.
Ultrasonic guided wave techniques have great potential for structural health monitoring applications. Appropriate mode and frequency selection is the basis for achieving optimised damage monitoring performance.
In this paper, several important guided wave mode attributes are
introduced in addition to the commonly used phase velocity and group velocity dispersion curves while using the general corrosion problem as an example. We first derive a simple and generic wave excitability function based on the theory of normal mode expansion and the reciprocity theorem. A sensitivity dispersion curve is formulated based on the group velocity dispersion curve. Both excitability and sensitivity dispersion curves are verified with finite element simulations. Finally, a
goodness dispersion curve concept is introduced to evaluate the tradeoffs between multiple mode selection objectives based on the wave velocity, excitability and sensitivity.
Austenitic welds are widely used in nuclear, petrochemical and process industries. The strong material anisotropy and coarse grain structure in the dendritic weld zone makes these welds very difficult to inspect with conventional techniques. It is well-known that the shear horizontal (SH) wave is well-suited for this inspection and that electromagnetic acoustic transducer (EMAT) is the best technique for generating this wave mode, but the lack of equipment has precluded its application in the field. This paper presents the development of one channel and phased array EMAT systems and results from tests conducted on samples provided by the Electric Power Research Institute (EPRI). The results show the potential of this new equipment
for austenitic weld inspection, which opens up new possibilities for research and field use.
In metallurgy, cladding refers to the bonding together of dissimilar metals, normally achieved by extruding two or more metals through a die or pressing sheets together under high pressure. Timely detection of delamination that occurs occasionally during the cladding processes is very important for the industry. This paper presents an EMAT system based on ultrasonic guided wave techniques. The analysis of a three-layer, brass/copper/brass product is also presented including dispersion curves, and interaction of ultrasonic guided wave with delamination defects. The authors observed a cyclic behavior of guided wave propagation with the increase of defect size. An explanation is introduced and proved with finite element analysis. The results presented in this paper will have a very significant impact on understanding of delamination detection in multilayered composite structures including adhesive bonded structures.
Camera Encoded Phased Array for Semi-Automated Inspection of Complex Composit...Innerspec Technologies
This paper introduces a new wireless solution that permits performing accurate and traceable ultrasonic scans of components with complex geometries using a hand-held scanner. The system integrates an array of 3D cameras that track the position of the hand of the inspector with a high-performance PAUT instrument to provide accurate, highresolution C-Scans on any component. This paper provides results of hand-held scans on complex composite parts,
and explores how the solution compares with traditional semi-automatic and automatic systems in terms of setup, ease-of-use, performance, productivity, and cost.
While an EMAT (Electro Magnetic Acoustic Transducer) in its simplest form is comprised of a magnet and an RF coil used to generate sound by electromagnetic induction in materials it is actually a rather complex system where each part of the sensor and instrumentation needs careful optimization for application specific performance. Historically EMAT inspection has suffered in widespread use because of a fundamental problem with the technology which is transducer inefficiency. EMAT requires very high power and very precise electronic designs to generate and
detect the signals.
Corrosion detection under pipe supports using EMAT Medium Range Guided WavesInnerspec Technologies
Corrosion detection under pipe supports is a recurrent problem in petrochemical and other process industries, with limited inspection alternatives due to the lack of immediate access to the corroded area. Long-Range UT (LRUT) has been used for years to inspect inaccessible areas but the large blind zone, limited resolution, and complex interpretation makes it difficult to field for this application.
EMAT-generated Medium-Range UT (MRUT) addresses these limitations and provides a robust and proven solution to the problem. EMAT is a non-contact technique that can generate guided waves without couplant or pressure, and permits scanning the part with a single tranducer on parts without surface preparation. Using a single Shear Horizontal and Lamb wave transducer, EMAT MRUT provides excellent near field resolution (no blind zone) and it can detect defects ten times
smaller than LRUT. EMAT MRUT is easy to field, and requires limited training.
Innerspec Technologies will present the MRUT technique with special focus on practical examples of their experience in the field.
Visit www.innerspec.com
Handheld Solution for Measurement of Residual Stresses on Railway Wheels usin...Innerspec Technologies
The braking process used on railroad cars is known to create tensile stresses in the circumferential direction due to the thermal expansion and subsequent cooling of the wheel rim. This tensile stress can significantly accelerate the growth of small cracks on the rolling surface which can cause a spall or catastrophic failure
of the wheel under load. By periodically evaluating the tensile stress, railroad companies can prevent wheel failures and derailments that can be extremely dangerous and costly. Innerspec Technologies has developed the first, portable, battery-operated handheld instrument that can be used to provide rail-side inspections and facilitate operation in any environment. The instrument is coupled with a proprietary, patent-pending, dual-channel sensor that does not need to be rotated during inspection thus simplifying the operation, increasing the reliability and accuracy of results, and reducing complexity and inspection cycle time.
KuberTENes Birthday Bash Guadalajara - K8sGPT first impressionsVictor Morales
K8sGPT is a tool that analyzes and diagnoses Kubernetes clusters. This presentation was used to share the requirements and dependencies to deploy K8sGPT in a local environment.
CHINA’S GEO-ECONOMIC OUTREACH IN CENTRAL ASIAN COUNTRIES AND FUTURE PROSPECTjpsjournal1
The rivalry between prominent international actors for dominance over Central Asia's hydrocarbon
reserves and the ancient silk trade route, along with China's diplomatic endeavours in the area, has been
referred to as the "New Great Game." This research centres on the power struggle, considering
geopolitical, geostrategic, and geoeconomic variables. Topics including trade, political hegemony, oil
politics, and conventional and nontraditional security are all explored and explained by the researcher.
Using Mackinder's Heartland, Spykman Rimland, and Hegemonic Stability theories, examines China's role
in Central Asia. This study adheres to the empirical epistemological method and has taken care of
objectivity. This study analyze primary and secondary research documents critically to elaborate role of
china’s geo economic outreach in central Asian countries and its future prospect. China is thriving in trade,
pipeline politics, and winning states, according to this study, thanks to important instruments like the
Shanghai Cooperation Organisation and the Belt and Road Economic Initiative. According to this study,
China is seeing significant success in commerce, pipeline politics, and gaining influence on other
governments. This success may be attributed to the effective utilisation of key tools such as the Shanghai
Cooperation Organisation and the Belt and Road Economic Initiative.
Low power architecture of logic gates using adiabatic techniquesnooriasukmaningtyas
The growing significance of portable systems to limit power consumption in ultra-large-scale-integration chips of very high density, has recently led to rapid and inventive progresses in low-power design. The most effective technique is adiabatic logic circuit design in energy-efficient hardware. This paper presents two adiabatic approaches for the design of low power circuits, modified positive feedback adiabatic logic (modified PFAL) and the other is direct current diode based positive feedback adiabatic logic (DC-DB PFAL). Logic gates are the preliminary components in any digital circuit design. By improving the performance of basic gates, one can improvise the whole system performance. In this paper proposed circuit design of the low power architecture of OR/NOR, AND/NAND, and XOR/XNOR gates are presented using the said approaches and their results are analyzed for powerdissipation, delay, power-delay-product and rise time and compared with the other adiabatic techniques along with the conventional complementary metal oxide semiconductor (CMOS) designs reported in the literature. It has been found that the designs with DC-DB PFAL technique outperform with the percentage improvement of 65% for NOR gate and 7% for NAND gate and 34% for XNOR gate over the modified PFAL techniques at 10 MHz respectively.
Water billing management system project report.pdfKamal Acharya
Our project entitled “Water Billing Management System” aims is to generate Water bill with all the charges and penalty. Manual system that is employed is extremely laborious and quite inadequate. It only makes the process more difficult and hard.
The aim of our project is to develop a system that is meant to partially computerize the work performed in the Water Board like generating monthly Water bill, record of consuming unit of water, store record of the customer and previous unpaid record.
We used HTML/PHP as front end and MYSQL as back end for developing our project. HTML is primarily a visual design environment. We can create a android application by designing the form and that make up the user interface. Adding android application code to the form and the objects such as buttons and text boxes on them and adding any required support code in additional modular.
MySQL is free open source database that facilitates the effective management of the databases by connecting them to the software. It is a stable ,reliable and the powerful solution with the advanced features and advantages which are as follows: Data Security.MySQL is free open source database that facilitates the effective management of the databases by connecting them to the software.
6th International Conference on Machine Learning & Applications (CMLA 2024)ClaraZara1
6th International Conference on Machine Learning & Applications (CMLA 2024) will provide an excellent international forum for sharing knowledge and results in theory, methodology and applications of on Machine Learning & Applications.
6th International Conference on Machine Learning & Applications (CMLA 2024)
Detection of internal defects prior to value-added processes
1. Detection of internal defects prior to value-added
processes to minimize final product surface defects
Jeffrey S. Monks
Sales and Marketing Director
Innerspec Technologies, Inc.
4004 Murray Place
Lynchburg, VA 24501
www.innerspec.com
2. INTRODUCTION
Final strip and sheet steel product is commonly inspected with great scrutiny to qualify material for
high-end product requirements. Surface flaws such as slivers, cracks, laps, etc., disqualify these
materials from being used in automotive and big box applications. Internal defects such as voids,
cracks, laminations, porosity and segregation may remain undetectable with surface inspection
methods as they have not yet manifested at the surface. These internal defects often propagate to
the surface where ultimately they are detectable in the finished product stage in the form of slivers,
blisters, etc., although remaining undetectable in the steel making, hot-rolling, pickling, cold rolling
and subsequent finishing operations. Surface flaws are a key cause of down grading of finished
product and a significant cost to the steel maker as all value added operations are complete before
detection and down grading are possible.
In today’s competitive environment, it is key to maximize utilization of mill assets and to avoid
adding value to material which can be known early in the manufacturing process to contain
deleterious defects. Using proven methods of volumetric material inspection in two separate case
studies, methods have been developed to allow the steel maker to identify poor material early in the
process thus avoiding the value added processes on these materials and only processing materials
which with a probability of final inspection passage.
CLAD METALS IN COIN STOCK
A recent application of strip inspection was for the inspection of clad coin stock material. In recent
years (late 1960’s) most worldwide coinage transitioned from solid precious metals (gold, silver,
copper) to a multi-layered clad material comprised mostly of a copper core and outer layers of alloy
to appear silver or gold but wear longer and obviously cost far less to produce.
Figure 1: Multi-Layered Clad Coin Stock Sample Showing area of disbond occurrence
AVAILABLE TEST METHODS:
Previous common methods of clad coin stock inspection available are, as in the steel industry,
Visual inspection (manually or automated) and ultrasonic normal beam inspection. Since visual
inspection can only detect surface discontinuities it is not suitable for disbond (internal) defect
detection. Ultrasonic Normal beam inspection relies on ultrasound being sent through a material
from the front surface to the back wall where the sound is reflected and then being seen again on
the front surface. The time required to send and receive this ultrasonic energy is directly
proportional to the material thickness. This method is referred to as “time-of-flight” as it is the time
required for the reflected sound to return to the sensor than indicates the material thickness.
When the material possesses an internal flaw, a portion of the ultrasonic energy is reflected earlier
in time than if the sound had traveled to the back wall of the material. This results in a decreased
time-of-flight and indicates either a material thickness change or an internal reflector (defect) is
present. In most strip materials (solid and clad) the thickness of the material is well controlled, so a
decreased time-of-flight is normally indicative of an internal flaw.
3. Figure 2: Normal Beam Method, and Time of Flight “A-Scan” Showing Material Back Wall and Internal Flaw Signal
While normal beam inspection is the historical method of choice using piezoelectric sensors it has a
few very important shortcomings:
It requires very precise positioning of sensors to reflect from the backwall
It uses a liquid couplant to transmit the sound from the transducer into the material
Sensors have a limited beam width so a large number of sensors are required to inspect an
entire strip width which may be up 7’ in length.
With piezoelectric ultrasonic inspection, sensor alignment is critical to ensure sound will travel to
the back wall and reflect back to the sensor. This alignment is very difficult in automated
environments as strip material typically has curvature, camber and irregular surface conditions.
When a piezoelectric sensor is not perfectly aligned to a parallel surface, sound is sent into the
strip at an angle and does not reflect back to the sensor. This is because the sound is generated
in the sensor and transduced into the material under inspection via a layer of liquid couplant. The
need for perfect alignment is a well-known limitation of this technique and normally requires costly
material handling equipment to ensure the best possible alignment to the material.
The couplant used for the transmission of sound also poses important constraints. Couplant
needs to be maintained with minimum turbulence and free of bubbles and contamination to avoid
ghost reflections, which are difficult to ensure at speeds of over 1m/s.
Another drawback to this method is cost. A typical piezoelectric sensor is 1” in diameter or less.
Because the entire strip needs to be inspected, the normal beam piezoelectric method requires
dozens of sensors. Being that each sensor requires electronics to perform the inspection, the
cost of a normal beam inspection system is extremely high.
THE EMAT SOLUTION
One of the most significant UT developments of the last 20 years is the advent of non-contact
solutions that do not require coupling, such as Electro Magnetic Acoustic Transducers (EMAT),
used for ultrasonic testing of metals.
4. While the sound in piezoelectric
transducers is generated in the probe
and transmitted into the part through
the couplant, an EMAT induces
ultrasonic waves into a test object with
two interacting magnetic fields. A
relatively high frequency (RF) field
generated by electrical coils interacts
with a low frequency or static field
generated by magnets to generate a
Lorentz force in a manner similar to
an electric motor. This disturbance is
transferred to the lattice of the
material, producing an elastic wave.
In a reciprocal process, the interaction
of elastic waves in the presence of a magnetic field induces currents in the receiving EMAT coil
circuit. For ferromagnetic conductors, magnetostriction produces additional stresses that
enhance the signals to much higher levels than could be obtained by the Lorentz force alone.
Various types of waves can be generated using different combinations of RF Coils and Magnets.
EMATs have all the benefits of ultrasonic testing, but because the sound is generated in the part
inspected, they enjoy some unique advantages for strip and clad inspection:
Dry Inspection (no couplant). Not having couplant permits more reliable readings (no
couplant errors) and makes this technology easier to automate and integrate in production.
High inspection speeds and high temperatures are also a fundamental advantage of EMATs.
Insensitive to Surface Conditions. EMATs are not sensitive to oxides, oil, water or uneven
surfaces and can inspect through thin coatings of material.
Unique Wave Modes. Because they do not depend on liquid to transmit the sound, EMATs
can generate some guided wave modes that are not available or very difficult and impractical
to generate with piezoelectric transducers.
Time-of-flight and amplitude inspection methods can replace dozens of channels of
piezoelectric ultrasonic equipment which would be required for Normal Beam strip inspection.
The main disadvantage of EMAT is the low efficiency of the transducer which requires high
voltages and very precise electronic designs to generate and detect the signals. These
disadvantages have become less relevant with the advent of new electronics and software that
enhance complex signal processing in real time. Additionally new proprietary Modeling software
and Finite Element Analysis tools have perfected the tedious task of EMAT sensor design.
INSPECTION WITH GUIDED WAVES
It is possible to generate any ultrasonic wave mode with EMAT inspection that is possible with
piezoelectric ultrasonic inspection. EMAT is also capable of generating unique guided waves
which are very difficult to generate with the piezoelectric method. Figure 4 compares wave
modes available for piezoelectric and EMAT ultrasonic methods. Lamb waves were determined
to be the wave mode of choice for clad inspection for their sensitivity to material thickness, where
in single layer materials, a combination of Raleigh (surface) waves, Lamb and Shear Horizontal
waves provide detection of an array of defect types, both internal and surface breaking.
Figure 3: Comparison of piezoelectric and EMAT sound generation
5. Wave Types in Solids Particle Motion Technique*
Longitudinal Parallel to wave direction Piezo, EMAT
Shear Vertical Perpendicular to wave direction Piezo, EMAT
Shear Horizontal
Perpendicular to wave direction on
a horizontal plane
EMAT
Surface – Rayleigh Elliptical orbit - symmetrical mode Piezo, EMAT
Surface – Bleustein-
Gulyaev
Piezo, EMAT
Plate Wave – Lamb
Component perpendicular to
surface (extensional wave)
EMAT
Plate Wave – Love
Parallel to plane layer,
perpendicular to wave direction
Piezo, EMAT
Stoneley (Leaky Rayleigh) Wave guided along interface Piezo, EMAT
Sezawa Antisymmetric mode Piezo, EMAT
Figure 4: Types of Waves in Piezoelectric and EMAT Ultrasonic Methods
A guided wave is one which propagates constrained by boundaries such as a surface, a plate, a
tube, rod or pipe, rail or other structure. Ultrasonic guided waves can travel from centimeters to
tens of meters in a structure. Guided waves that are constrained by top and bottom surfaces are
referred to as plate wave. Plate waves are Raleigh, Lamb or Shear Horizontally polarized waves.
Guided Wave Test Methods
The use of guided waves offers essentially 3 methods of defect detection. These are reflection
(where a wave strikes a defect and reflects back toward the sensor), time of flight measurement
(where the time a wave takes to propagate from point “A” to point “B” is monitored), and
amplitude (where the received signal is monitored for signal amplitude where the strength of the
signal determines the presence or absence of defects).
Inspection of strip material for laminations using guided waves has important benefits over the
conventional normal beam approach. Whereas piezoelectric transducers must send ultrasonic
energy from the top surface to the back surface to measure time-of-flight, an EMAT-generated
guided wave fills up the full volume of the material and permits inspection of the full strip width at
line speeds with a small number of sensors.
When Lamb waves encounter a thickness change in a structure they propagate at a different
velocity. As a material becomes thinner, the wave moves at a higher velocity through the thin
section than the thicker sections. This sensitivity to thickness characteristic of Lamb waves make
it the ideal wave mode for clad material bond testing (or lamination detection in single layer
Figure 5: Reflection and Time of flight / Amplitude Methods of Detection with Guided Waves
6. materials) as an area of disbond/lamination will split the Lamb wave into two separate waves (one
on top and bottom of the disbonded area which effects the velocity of the wave propagation and
therefore the time of flight of this wave from one side of the material width to the other).
EXPERIENCE WITH SINGLE LAYER MATERIAL INSPECTION (STEEL STRIP)
The first commercial system for inspection of thin strip using guided waves was first introduced by
Innerspec Technologies in the late 1990’s. The temate®
Pi-GW (originally introduced as temate®
4000) was designed to detect sub-surface defects such as pencil pipe, laminations and porosity,
and surface defects such as cracks and slivers in steel strip before cold rolling. Using lamb
waves the system was able to inspect material from 1.5mm to 10mm at speeds of 400m/minute
and detect defects as small as 0.07mm in thickness using the reflection method.
Figure 6: First EMAT system for Guided Wave Strip Inspection for Steel Strip Inspection
In initial testing, coils were visually inspected to identify surface defects after pickling. Analysis of
the defects detected with EMAT and found visually at different down-stream process indicates the
validity that an Ultrasonic EMAT inspection system can detect the presence of defects in the early
stages of manufacturing where down-grading material will result in cost savings. As shown on the
results table(figure 8), after pickling, 18 defects were detected with EMAT where visual examination
only detected 3 surface defects, indicating that 15 of the EMAT detected defects were internal and
not open or at the surface. After cold reduction, 7 defects were detectable visually and after electro-
galvanizing, 17 surface defects were visually detectable. In this single example, the coil could have
been downgraded after pickling saving the costs of running this material through cold reduction and
finishing operations.
Figure 7: Installation of EMAT system after Pickling and side view of Sensors
7. NEW ADVANCED TOOLS DEVELOPED
Our recent project with the supplier of coin stock material for a National Mint allowed the unique
opportunity to use advanced modeling and finite element analysis tools recently developed in-
house at Innerspec Technologies to aid in the efficient design of application specific EMAT
sensors along with the experience gained in the installation detailed previously on single layer
steel materials.
Figure 8 shows a metallurgical photo of the cross section of the three layered cladding product.
The normal thickness of the three layered structure is 0.064 inch in total and 0.016’’, 0.032’’, and
0.016’’ for the brass, copper, and brass layers respectively.
Figure 8: Metallurgical photo of the cross section of the three layered cladding product.
A Laboratory system was assembled and installed in an off line re-rolling location. This system
was tested for nearly 6 months and data was studied to continuously verify the results matched
the models developed. The guided wave EMAT method of strip inspection requires the use of a
separate transmitter and receiver held at a fixed mechanical distance from each other. In a
generally homogenous material, the time of flight of the transmitted signal to the receiver and the
amplitude of the received signal is near constant. By closely monitoring the time of reception of
the EMAT generated ultrasonic energy and the amplitude of this signal, the presence of defects in
strip materials can easily be detected.
Figure 9: Trial System Installed off line for modeling verification and Signal variance at disbond
Since the installation of this system, the customer has given positive feedback about the success
in both artificial and real defect detection. Several sample scans are shown in Figures 10-12. The
first is a disbond intentionally added during manufacturing. The second is a natural fabrication
defect at the edge of the strip, with around 14’’ length and 2.5’’ wide into the strip. The third is a
natural defect detected with EMAT system. This sample section was isolated and processed
through the coin planchet punch and rimming operations. In the stamping trial, three coins (0.94”
dia) contained the disbond of approximately 0.3” wide at the same cross-web location. These
coins came from the exact location that had been previously marked based on spikes seen in
EMAT system. Other defects found from EMAT automatic system were also verified with
ultrasonic bulk wave spot checking instruments.
8. Figure 10: Artificial lamination 0.7’’ wide
Figure 11: Natural defect on the edge with 14’’ long and 2.5’’ wide into the strip
Figure 12: Natural defect about 3 inch long and 0.3’’ wide
Ultimately a production system was designed and installed to operate in-line at line speeds.
Since its installation, disbonded coin stock has been eliminated. New guided wave dispersion
curves have been developed for other types of coin stock clad alloy inspection. The operation is
fully automated and the system includes an automated paint marking system to identify
disbonded areas on the strips edge while processing.
The temate®
Pi-GW system has now been verified in operation on both single layer and multi-
layer clad materials. With the successful implementation of proprietary guided wave modeling
and finite element analysis 100% line speed inspection is available for single and multi-layer
materials. The results have been verified via destructive and off-line nondestructive methods.
EMAT generated guided waves are key to an in-line inspection of such materials as the EMAT
method is the only way to efficiently generate guided waves into a production inspection
environment.
Manufacturers can realize compelling return on investment by using this method of inspection far
upstream in the process to not add value to lower quality materials which are prone to fail final
inspection.
9. Figure 13: temate®
Pi-GW system as installed at Clad Coin Stock Factory Front and rolling direction views