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Tinplating on steel is a useful industrial process extensively used for food packaging. Cold-rolled annealed steel coated with tin gives the steel corrosion resistance property and a beautiful luster. Tinplating on steel is a complex... more
Tinplating on steel is a useful industrial process extensively used for food packaging. Cold-rolled annealed steel coated with tin gives the steel corrosion resistance property and a beautiful luster. Tinplating on steel is a complex process where rolled and annealed steel sheets are cleaned with acid to remove rust, grease, or oil from the surface. Pure tin is electrodeposited on this freshly prepared surface after the electrodeposition of tin on the steel strip; the surface becomes lustrous, the color of pure tin appears, and the finish is called matte. Very often, the flowing heat treatment is just about the tin melting point of 232°C–265°C. After electrodeposition, pure tin deposits on the steel surface; however, a chemical reaction between tin and iron occurs during the brightening treatment. This process results in iron–tin intermetallic formation; their orientation grain structure and orientation of substrate steel all have a synergistic effect on the final properties of tin-...
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ABSTRACT
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ABSTRACT
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Nanoparticles, when homogeneously dispersed in a base fluid, e.g. water, ethylene glycol etc. are commonly known as nanofluids. Nanofluids have gained attention in the scientific community for their enhanced thermal properties. One of the... more
Nanoparticles, when homogeneously dispersed in a base fluid, e.g. water, ethylene glycol etc. are commonly known as nanofluids. Nanofluids have gained attention in the scientific community for their enhanced thermal properties. One of the major problems in using nanofluids as a heat transfer medium for commercial applications is that, in most of the closed circuit industrial cooling processes, the cooling fluid has to be replaced after several cycles of cooling operation because of an increased presence of contaminants. If nanofluids were used as a coolant, it would be very hard to separate the nanoparticles from the waste fluid. The present work is aimed at the separation and recycling of nanoparticles from fluid waste by means of quick settling of titanium dioxide nanoparticles using silver nanoparticles along with ultrasonic treatment. It is observed that with increasing silver concentration and time of ultrasonication, the stability of the dispersion decreases. There is a value for both the silver concentration and ultrasonication time above which the settling time decreases drastically.
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ABSTRACT Two interstitial free high strength (IFHS) steels of comparable chemistries but processed through batch annealing and continuous annealing routes have been studied. The near absence of FeTiP and presence of a large volume... more
ABSTRACT Two interstitial free high strength (IFHS) steels of comparable chemistries but processed through batch annealing and continuous annealing routes have been studied. The near absence of FeTiP and presence of a large volume fraction of TiC are considered to be primarily responsible for the sharp {1 1 1} texture in the CA steel.
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Two dissimilar advanced high strength steels (AHSS)—ferrite-bainite (F-B) and ferrite-martensite (F-M) steel grades were joined by gas metal arc welding (GMAW) process. Microstructure of the heat-affected zone (HAZ) after welding was... more
Two dissimilar advanced high strength steels (AHSS)—ferrite-bainite (F-B) and ferrite-martensite (F-M) steel grades were joined by gas metal arc welding (GMAW) process. Microstructure of the heat-affected zone (HAZ) after welding was critically reviewed and further correlated with the performance of the welded joint. It was observed that both the steels had softening in the HAZ, particularly in the intercritical HAZ (ICHAZ) although the reasons were found to be different. For the F-B steel grade, the extent of softening was much higher and primarily attributed to the annihilation of the dislocations (which was manifested by presence of internal strain) present in the base matrix. Besides, the volume fraction of the precipitates present in the base steel was also reduced drastically and aided in the softening process. In contrast, the F-M steel inherently contained less internal strain and the softening was predominantly due to the tempering of the martensite islands distributed in the ferrite matrix during the welding process. Thus, to extract the optimum benefits from these modern AHSSs after welding, it is important to have a thorough knowledge about the steel design philosophy (i.e., base metal chemistry and transformed microstructural products).
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Abstract Two plain carbon steel plates were joined by magnetic pulse welding process. The optimum condition was found to be 16 kV discharge voltage and 0.8 mm standoff distance for the present set of plates. Three distinct zones of... more
Abstract Two plain carbon steel plates were joined by magnetic pulse welding process. The optimum condition was found to be 16 kV discharge voltage and 0.8 mm standoff distance for the present set of plates. Three distinct zones of bonding namely; solid state bonding, homogeneous liquid state bonding and liquid state bonding with pores and cracks were observed. Any appreciable changes observed were restricted within 5 μm distance from the weld line. Microstructural as well as crystallographic alterations of the structures were not detected beyond 5 μm.
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Three distinct layers are present in commercially produced tinplated steels: the top tin layer, the middle Fe-Sn alloy layer, and the bottom steel substrate. The brightness of these steels is inversely proportional to the roughness of the... more
Three distinct layers are present in commercially produced tinplated steels: the top tin layer, the middle Fe-Sn alloy layer, and the bottom steel substrate. The brightness of these steels is inversely proportional to the roughness of the top layer. Substrate steels with recrystallized structure, sharper texture, and cleaner matrix result in flatter Fe-Sn interlayer and subsequently smoother top Sn layer. This in turn gives brighter surface finish.
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The importance of TWinning Induced Plasticity (TWIP) and TRansformation Induced Plasticity (TRIP) has increased drastically in the recent past due their potential for automobile applications. These steels have good combination of specific... more
The importance of TWinning Induced Plasticity (TWIP) and TRansformation Induced Plasticity (TRIP) has increased drastically in the recent past due their potential for automobile applications. These steels have good combination of specific strength and ductility, which could improve the crash resistance or energy absorption capacity in the situations like accidents. Stacking Fault Energy (SFE) is the most important parameter for the design of such steels. In low SFE TWIP steels, Brass (Bs)-type texture typically develops during rolling. Present investigation deals with the role of deformation texture, microstructure and SFE in recrystallization kinetics and grain growth, during processing in medium Mn steels. The SFE of Fe-12Mn-0.5C (wt %) alloy could be altered by the addition of alloying elements, such as Al. Recrystallization experiments have been carried out in cold rolled samples for different annealing times. In order to understand the recrystallization kinetics and grain growth phenomenon, detailed microstructural characterization has been performed by using Electron back-scatter diffraction (EBSD).
The magnetic properties of non-oriented electrical steels are determined by a combination of several metallurgical variables, including crystal orientation, misorientation (the orientation difference between two crystal orientations), and... more
The magnetic properties of non-oriented electrical steels are determined by a combination of several metallurgical variables, including crystal orientation, misorientation (the orientation difference between two crystal orientations), and the amount of residual stress associated with plastic deformation. These variables are influenced by cold rolling and annealing. In order to study these relationships, samples in the semi-processed condition were subjected to an additional cold roll and a subsequent annealing at different temperatures, and then characterized using electron backscatter diffraction and nanoindentation. The process routing for these samples was not intended to be representative of real-world manufacturing; the purpose was to produce a spread in the metallurgical variables being investigated. Although some trends were observed involving orientation and misorientation, when present, deformation observed close to grain boundaries appeared to be the most influential variable on the magnetic properties.
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ABSTRACT The coercivity and hysteresis losses of non-oriented electrical steels (NOES) are determined by metallurgical parameters evolved during their manufacturing process. Although the links between grain size, inclusion content,... more
ABSTRACT The coercivity and hysteresis losses of non-oriented electrical steels (NOES) are determined by metallurgical parameters evolved during their manufacturing process. Although the links between grain size, inclusion content, orientation and these magnetic properties are well established, the effects of misorientation, especially with respect to the magnetic easy axis, are mostly unexplored. From this work examining NOES samples with “typical” grain size and inclusion distributions, but with texture variations induced by lab processing, the major factors determining the coercivity and hysteresis losses were limited to the magnetocrystalline anisotropy energy (Ea) and EAM, a newly created easy axis misorientation parameter. It is believed that Ea is a measure of the contribution of domain rotation processes, while EAM is a representation of the ability of the sample to nucleate reverse magnetic domains. The utilization of EAM allows for a better understanding of the influence of metallurgical parameters on the magnetic properties, especially for samples with large differences in processing and texture.
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Cold rolled and annealed interstitial free high strength (IFHS) steels show various kinds of precipitates. Out of these, FeTiP is the most deleterious, since its formation leads to a loss of strength as well as degradation of the... more
Cold rolled and annealed interstitial free high strength (IFHS) steels show various kinds of precipitates. Out of these, FeTiP is the most deleterious, since its formation leads to a loss of strength as well as degradation of the formability of the steel. This effect is much more pronounced in batch annealed IFHS steels than in their continuous annealed counterparts. The
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... Ghosh et al 10 have studied the precipitation behavior and texture formation in two IFHS steels of almost similar chemistries but processed through different annealing routes; batch annealing (BA) and continuous annealing (CA) (see... more
... Ghosh et al 10 have studied the precipitation behavior and texture formation in two IFHS steels of almost similar chemistries but processed through different annealing routes; batch annealing (BA) and continuous annealing (CA) (see Table 2). The batch annealed steel shows ...
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ABSTRACT Precipitation and texture formation in two cold rolled and batch-annealed interstitial-free high strength steels have been studied. TiN, Fe(Ti + Nb)P and TiC were the main precipitates observed. A perceptibly higher population of... more
ABSTRACT Precipitation and texture formation in two cold rolled and batch-annealed interstitial-free high strength steels have been studied. TiN, Fe(Ti + Nb)P and TiC were the main precipitates observed. A perceptibly higher population of Fe(Ti + Nb)P precipitates in the steel containing a higher amount of P is considered to be primarily responsible for the less intense {1 1 1} texture.
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Abstract Quantitative physical models for non-oriented electrical steels require precise knowledge of chemical and microstructural parameters for the material, with crystallographic texture being one of the most important. Describing the... more
Abstract Quantitative physical models for non-oriented electrical steels require precise knowledge of chemical and microstructural parameters for the material, with crystallographic texture being one of the most important. Describing the structure–property relationships in these materials is made difficult in that all of the parameters have an effect on magnetic properties. In the present study, a set of non-oriented electrical steel specimens are examined, where chemistry and grain size are kept similar from sample to sample, but texture is varied. A new texture parameter called Magnetic Texture Factor is introduced which is defined as the ratio of the volume fractions of 〈100〉 direction to 〈111〉 direction along magnetization vector. It was found that this Magnetic Texture Factor was a better parameter for identifying trends of magnetic properties with crystallographic texture than the often used Texture Factor , which is described as the ratio of the volume fractions of {100} planes to {111} planes.
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Abstract The microstructural, textural evolution and changes in grain boundary character distribution during annealing of a prior cold worked (30 %, 50 % and 80 %) ferrite–bainite dual phase steel have been studied and correlated with... more
Abstract The microstructural, textural evolution and changes in grain boundary character distribution during annealing of a prior cold worked (30 %, 50 % and 80 %) ferrite–bainite dual phase steel have been studied and correlated with mechanical properties. It has been shown that submicron sized subgrains can be obtained by selecting the appropriate amount of cold rolling and annealing cycle. Increasing the annealing temperature in all the materials produces the expected results, namely decrease in strength with a simultaneous increase in ductility. Although reasonably sharp γ-fibres were obtained in 80 % cold rolled and its 500 °C annealed counterpart, the very low values (< 1.0) make the steel unsuitable for the purpose of deep drawing. It is envisaged that grain boundary engineering may lead to better strength–ductility combinations in this steel for an enhanced range of applications.
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... Critical assessment and thermodynamic modeling of Mg–Zn, Mg–Sn, Sn–Zn and Mg–Sn–Zn systems. P. Ghosh a , M. Mezbahul-Islam a , M. Medraj Corresponding Author Contact Information , a , E-mail The Corresponding Author. ...
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ABSTRACT Two interstitial free high strength (IFHS) steels of comparable chemistries but processed through batch annealing and continuous annealing routes have been studied. The near absence of FeTiP and presence of a large volume... more
ABSTRACT Two interstitial free high strength (IFHS) steels of comparable chemistries but processed through batch annealing and continuous annealing routes have been studied. The near absence of FeTiP and presence of a large volume fraction of TiC are considered to be primarily responsible for the sharp {1 1 1} texture in the CA steel.
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ABSTRACT
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Industrial production of modern interstitial free (IF) steels began some 40 years ago. Since then, with the development of the automotive sector, production of IF steels has increased remarkably rapidly. However, with increased global... more
Industrial production of modern interstitial free (IF) steels began some 40 years ago. Since then, with the development of the automotive sector, production of IF steels has increased remarkably rapidly. However, with increased global awareness of the effects of industry on the ...
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Nanoparticles, when homogeneously dispersed in a base fluid e.g water, ethylene glycol etc. are commonly known as Nanofluids. Nanofluids have gained attention in the scientific community for their enhanced thermal properties. One of the... more
Nanoparticles, when homogeneously dispersed in a base fluid e.g water, ethylene glycol etc. are commonly known as Nanofluids. Nanofluids have gained attention in the scientific community for their enhanced thermal properties. One of the major problems in using nanofluids as a heat transfer medium for commercial applications is that, in most of the closed circuit industrial cooling processes, the cooling fluid has to be replaced after several cycles of cooling operation because of an increased presence of contaminants. If nanofluids were used as a coolant, it would be very hard to separate the nanoparticles from the waste fluid. The present work is aimed at the separation and recycling of nanoparticles from fluid waste by means of quick settling of titanium dioxide nanoparticles using silver nanoparticles along with ultrasonic treatment. It is observed that with increasing silver concentration and time of ultrasonication, the stability of the dispersion decreases. There is a value fo...
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A systematic and detailed characterization of precipitates, as a function of steel composition, has been carried out in five batch-annealed interstitial-free high-strength steels. The precipitation behavior has been discussed from the... more
A systematic and detailed characterization of precipitates, as a function of steel composition, has been carried out in five batch-annealed interstitial-free high-strength steels. The precipitation behavior has been discussed from the point of view of thermodynamics as well as on the basis of the kinetics. An attempt has been made to explain the discrepancies between the thermodynamic prediction and the actual observations. Finally, the correlation between precipitation and textural evolution and deep drawability has been critically investigated.
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ABSTRACT
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Interstitial free steels, commonly known as interstitial free (IF) steels, are widely used by auto manufacturers on account of their excellent formability as compared to other steels. As the name suggests, IF steels are almost free of... more
Interstitial free steels, commonly known as interstitial free (IF) steels, are widely used by auto manufacturers on account of their excellent formability as compared to other steels. As the name suggests, IF steels are almost free of interstitial elements, C and N, and this IF matrix results in excellent formability. In IF steels, C and N are kept very low