Kumkum Banerjee - Academia.edu (original) (raw)
Papers by Kumkum Banerjee
Materials Science and …, 2008
... and the mode of graphitisation by using alloying elements or by heat treatment, is not ... Th... more ... and the mode of graphitisation by using alloying elements or by heat treatment, is not ... The effect of cold working on the graphitisation of aluminium killed cold rolled steel was investigated by ... that extreme reduction of P and S accelerated graphitisation in hypoeutectoid steels and ...
Materials Science and …, 2008
... and the mode of graphitisation by using alloying elements or by heat treatment, is not ... Th... more ... and the mode of graphitisation by using alloying elements or by heat treatment, is not ... The effect of cold working on the graphitisation of aluminium killed cold rolled steel was investigated by ... that extreme reduction of P and S accelerated graphitisation in hypoeutectoid steels and ...
Materials Science and Technology
... and the mode of graphitisation by using alloying elements or by heat treatment, is not ... Th... more ... and the mode of graphitisation by using alloying elements or by heat treatment, is not ... The effect of cold working on the graphitisation of aluminium killed cold rolled steel was investigated by ... that extreme reduction of P and S accelerated graphitisation in hypoeutectoid steels and ...
Metallurgical and Materials Transactions A
Materials Science Forum, Apr 26, 2012
ABSTRACT Non-isothermal austenite grain growth kinetics has been studied in a microalloyed linepi... more ABSTRACT Non-isothermal austenite grain growth kinetics has been studied in a microalloyed linepipe steel with complex precipitates containing Ti, Nb and/or Mo. The goal of these experimental studies is to provide the basis for the development of a grain growth model to predict the austenite grain size evolution in the weld heat affected zone (HAZ). Detailed electron microscopic investigations of the as received steel proved the presence of Ti-rich, Nb-rich and Mo-rich precipitates. The steel was subjected to austenitizing heat treatments to selected peak temperatures of 950, 1150 and 1350 °C at heating rates of 10, 100 and 1000 °C/s, respectively. Thermal cycles have been found to have a strong effect on the austenite grain size. Austenite grain sizes increase with peak temperature and decreasing heating rate. However, the increase in heating rate from 100 to 1000 °C/s has a negligible effect on the austenite grain size. The observed austenite grain growth kinetics can be explained taking into account the potential dissolution of Nb-rich precipitates.
International Journal of Metallurgical Engineering, 2013
Advanced high strength steels (AHSS) are several families of steels (dual phase, transformation-i... more Advanced high strength steels (AHSS) are several families of steels (dual phase, transformation-induced plasticity, co mplex phase and martensitic steels) that constitute ferrite along with low temperature phases-martensite, bainite and/or retained austenite, in adequate quantities, to obtain desired mechanical properties. These steels find their applications in automobiles and are able to enhance mechanical properties with reduced weight that make them cost effective, fuel efficient and environment friendly. All AHSS are produced using proper chemistry design in association with controlled rate of cooling fro m the austenite-ferrite phase region, either on the run-out table in a hot rolling mill or in the cooling section of a continuous annealing line. This ensures high strength and other desired properties essentially through the low temperature phase transformation products. In the present investigation, the base metal microstructure had played a key ro le in dictating tensile properties and weldability of spot welded AHSS in simulated continuously annealed conditions. A few miocroalloyed AHSS with low carbon equivalent were produced in a laboratory air induction furnace and were subsequently hot forged and rolled in the laboratory. Continuous heating and cooling transformations were vividly studied in a Gleeble 1500D to determine intercrit ical temperature reg imes and the transformation temperatures in association with cooling rates of the lo w temperature transformation products. The hot rolled samples after duly cold rolled were submitted to strip annealing simu lation to mimic actual continuous annealing, employing a Gleeble 3500 thermo mechanical simulator. Two types of annealing cycles were simulated to examine the effect of cooling rate and bainite alongside fine microalloying precipitates on tensile properties and weldability. The annealing cycles that resulted in ferrite, 37% bainite and martensite in association with nano-sized Mo-C were successful in delivering the satisfactory combination of tensile properties and weldability.
Http Dx Doi Org 10 1080 10426910701233236, Apr 10, 2007
ABSTRACT
Journal of Materials Processing Technology, 2015
Recrystallization, 2012
High r m-values correlate well with good deep drawability (Lankford et al., 1950). Good drawabili... more High r m-values correlate well with good deep drawability (Lankford et al., 1950). Good drawability also diminishes the edge splitting tendency during hole-expansion tests (Klein & Hitchler, 1973). The favourable texture for good deep drawability is a large fraction of the grains oriented with {111} planes parallel to the plane of a sheet (Whiteley & Wise, 1962). To ensure satisfactory drawability in these steels, i. e. to increase the depth www.intechopen.com Recrystallization 138 of drawing and avoid the crack during deep drawing process and at the same time to make the edge on the top of a drawn cup smooth without the phenomenon of earing, the deep drawing sheet is required to possess high plastic anisotropy, r m and low normal anisotropy, Δr. In other words, to maximize r m-value and minimize r-value, {111}<112> and {111}<110> components of -fiber (Figure 1) (Kestens et al., 1996) are the ideal crystallographic textures for deep drawing steel, because the correct texture gives the proper orientation of slip system so that the strength in the thickness direction is greater than that in the plane of the sheet. If {100} plane parallels rolling plane, the strength is lowest in the thickness direction of sheet. This, in turn, adversely influences the formability of the sheet. The {111}/{l00} intensity ratio is reported to be linearly related to r m (Held, 1965) and can easily be determined using X-ray diffractometer measurements of the (222) and (200) lines.
Materials Sciences and Applications, 2011
The role of magnesium (Mg) in improving the high temperature mechanical properties of the superal... more The role of magnesium (Mg) in improving the high temperature mechanical properties of the superalloys, like creep, fatigue, tensile ductility, impact toughness etc. have been vividly studied by several authors. On the other hand, very few authors have contradicted the view of any beneficial effect of Mg on the mechanical properties. This review presents a summary of the open literature related to the effect of Mg on the microstructure and mechanical properties of superalloys and from which further metallurgical research on the unexamined topics are proposed.
Metallurgical and Materials Transactions A, 2003
ABSTRACT HSLA-80 and HSLA-100 steels have been subjected to weld-simulated grain-coarsened heat-a... more ABSTRACT HSLA-80 and HSLA-100 steels have been subjected to weld-simulated grain-coarsened heat-affected zone (GCHAZ) and grain-refined heat-affected zone (GRHAZ) treatments at peak temperatures of 1350 C and 950 C, respectively, followed by varying cooling rates to approximate the weld heat inputs of 10 to 50 kJ/cm. Subsequent slow strain rate testing in synthetic seawater has been employed to assess the hydrogen embrittlement (HE) propensity of the materials. It is indicated that in spite of an increase in strength after weld simulation, further ductility deterioration, compared to the base material under similar testing conditions, did not occur in GCHAZ HSLA-100 steel and for low heat input condition of GRHAZ HSLA-80. This has been attributed to their HE resistant microstructures. Predominant acicular ferrite or lath martensite or a combination of both imparts resistance to HE, as observed in the case of grain-coarsened HSLA-100 and for the low heat input grain-refined HSLA-80 steels. The deleterious effect of bainitic-martensitic microstructure has been reflected in the ductility values of grain-coarsened HSLA-80, which is in agreement with the observation of higher susceptibility of the as-received HSLA-100 steel having a similar structure. However, contrary to its beneficial effect in the as-received HSLA-80, an acicular ferrite structure has shown vulnerability toward HE for high heat input grain-refined HSLA-80. This has been attributed to the presence of polygonal ferrite and to the development of an HE susceptible substructure on GRHAZ weld simulation.
British Corrosion Journal, 2000
ABSTRACT Hydrogen embrittlement behaviour of an HSLA–80 steel in the weld simulated, grain coarse... more ABSTRACT Hydrogen embrittlement behaviour of an HSLA–80 steel in the weld simulated, grain coarsened heat affected zone condition, in synthetic sea water under cathodic charging in the applied potential range of -600 to -1400 mV(SCE) has been studied using a slow strain rate technique. Loss of ductility, as reflected in the percentage elongation and percentage reduction in area values, was substantial at and beyond -800 mV(SCE). The material in the weld simulated condition showed more susceptibility than the as received material, which is considered to be a result of increased strength and a bainitic–martensitic microstructure. Fracture showed both microvoid coalescence and quasi-cleavage features and was indicative of hydrogen induced void nucleation. Both hardening and softening effects on hydrogen charging were experienced.
Nonisothermal austenite grain growth kinetics under the influence of several combinations of Nb, ... more Nonisothermal austenite grain growth kinetics under the influence of several combinations of Nb, Ti, and Mo containing complex precipitates has been studied in a microalloyed linepipe steel. The goal of this study is the development of a grain growth model to predict the austenite grain size in the weld heat affected zone (HAZ). Electron microscopy investigations of the as-received steel proved the presence of Ti-rich, Nb-rich, and Mo-rich precipitates. The steel has then been subjected to austenitizing heat treatments to selected peak temperatures at various heating rates that are typical for thermal cycles in the HAZ. Thermal cycles have a strong effect on the final austenite grain size. Using a mean field approach, a model is proposed for the dissolution of Nb-rich precipitates. This model has been coupled to a Zener-type austenite grain growth model in the presence of pinning particles. This coupling leads to accurate prediction of the austenite grain size along the nonisothermal heating path simulating selected thermal profiles of the HAZ.
Scripta Materialia, 2001
... 2. EJ Czyryca, RE Link, RJ Wong, DA Aylor, TW Montemarano, and JP Gudas, Naval Eng. J. May, 6... more ... 2. EJ Czyryca, RE Link, RJ Wong, DA Aylor, TW Montemarano, and JP Gudas, Naval Eng. J. May, 63 (1990). 3. AD Wilson, J. Metals. ... 21. RC Frank, in Internal Stresses and Fatigue in Metals, ed. GM Rassweiler and WL Grube, p. 411, Elsevier, New York (1959). 22. ...
Metallurgical and Materials Transactions A, 2010
Nonisothermal austenite grain growth kinetics under the influence of several combinations of Nb, ... more Nonisothermal austenite grain growth kinetics under the influence of several combinations of Nb, Ti, and Mo containing complex precipitates has been studied in a microalloyed linepipe steel. The goal of this study is the development of a grain growth model to predict the austenite grain size in the weld heat affected zone (HAZ). Electron microscopy investigations of the as-received steel proved the presence of Ti-rich, Nb-rich, and Mo-rich precipitates. The steel has then been subjected to austenitizing heat treatments to selected peak temperatures at various heating rates that are typical for thermal cycles in the HAZ. Thermal cycles have a strong effect on the final austenite grain size. Using a mean field approach, a model is proposed for the dissolution of Nb-rich precipitates. This model has been coupled to a Zener-type austenite grain growth model in the presence of pinning particles. This coupling leads to accurate prediction of the austenite grain size along the nonisothermal heating path simulating selected thermal profiles of the HAZ.
Materials Science and …, 2008
... and the mode of graphitisation by using alloying elements or by heat treatment, is not ... Th... more ... and the mode of graphitisation by using alloying elements or by heat treatment, is not ... The effect of cold working on the graphitisation of aluminium killed cold rolled steel was investigated by ... that extreme reduction of P and S accelerated graphitisation in hypoeutectoid steels and ...
Materials Science and …, 2008
... and the mode of graphitisation by using alloying elements or by heat treatment, is not ... Th... more ... and the mode of graphitisation by using alloying elements or by heat treatment, is not ... The effect of cold working on the graphitisation of aluminium killed cold rolled steel was investigated by ... that extreme reduction of P and S accelerated graphitisation in hypoeutectoid steels and ...
Materials Science and Technology
... and the mode of graphitisation by using alloying elements or by heat treatment, is not ... Th... more ... and the mode of graphitisation by using alloying elements or by heat treatment, is not ... The effect of cold working on the graphitisation of aluminium killed cold rolled steel was investigated by ... that extreme reduction of P and S accelerated graphitisation in hypoeutectoid steels and ...
Metallurgical and Materials Transactions A
Materials Science Forum, Apr 26, 2012
ABSTRACT Non-isothermal austenite grain growth kinetics has been studied in a microalloyed linepi... more ABSTRACT Non-isothermal austenite grain growth kinetics has been studied in a microalloyed linepipe steel with complex precipitates containing Ti, Nb and/or Mo. The goal of these experimental studies is to provide the basis for the development of a grain growth model to predict the austenite grain size evolution in the weld heat affected zone (HAZ). Detailed electron microscopic investigations of the as received steel proved the presence of Ti-rich, Nb-rich and Mo-rich precipitates. The steel was subjected to austenitizing heat treatments to selected peak temperatures of 950, 1150 and 1350 °C at heating rates of 10, 100 and 1000 °C/s, respectively. Thermal cycles have been found to have a strong effect on the austenite grain size. Austenite grain sizes increase with peak temperature and decreasing heating rate. However, the increase in heating rate from 100 to 1000 °C/s has a negligible effect on the austenite grain size. The observed austenite grain growth kinetics can be explained taking into account the potential dissolution of Nb-rich precipitates.
International Journal of Metallurgical Engineering, 2013
Advanced high strength steels (AHSS) are several families of steels (dual phase, transformation-i... more Advanced high strength steels (AHSS) are several families of steels (dual phase, transformation-induced plasticity, co mplex phase and martensitic steels) that constitute ferrite along with low temperature phases-martensite, bainite and/or retained austenite, in adequate quantities, to obtain desired mechanical properties. These steels find their applications in automobiles and are able to enhance mechanical properties with reduced weight that make them cost effective, fuel efficient and environment friendly. All AHSS are produced using proper chemistry design in association with controlled rate of cooling fro m the austenite-ferrite phase region, either on the run-out table in a hot rolling mill or in the cooling section of a continuous annealing line. This ensures high strength and other desired properties essentially through the low temperature phase transformation products. In the present investigation, the base metal microstructure had played a key ro le in dictating tensile properties and weldability of spot welded AHSS in simulated continuously annealed conditions. A few miocroalloyed AHSS with low carbon equivalent were produced in a laboratory air induction furnace and were subsequently hot forged and rolled in the laboratory. Continuous heating and cooling transformations were vividly studied in a Gleeble 1500D to determine intercrit ical temperature reg imes and the transformation temperatures in association with cooling rates of the lo w temperature transformation products. The hot rolled samples after duly cold rolled were submitted to strip annealing simu lation to mimic actual continuous annealing, employing a Gleeble 3500 thermo mechanical simulator. Two types of annealing cycles were simulated to examine the effect of cooling rate and bainite alongside fine microalloying precipitates on tensile properties and weldability. The annealing cycles that resulted in ferrite, 37% bainite and martensite in association with nano-sized Mo-C were successful in delivering the satisfactory combination of tensile properties and weldability.
Http Dx Doi Org 10 1080 10426910701233236, Apr 10, 2007
ABSTRACT
Journal of Materials Processing Technology, 2015
Recrystallization, 2012
High r m-values correlate well with good deep drawability (Lankford et al., 1950). Good drawabili... more High r m-values correlate well with good deep drawability (Lankford et al., 1950). Good drawability also diminishes the edge splitting tendency during hole-expansion tests (Klein & Hitchler, 1973). The favourable texture for good deep drawability is a large fraction of the grains oriented with {111} planes parallel to the plane of a sheet (Whiteley & Wise, 1962). To ensure satisfactory drawability in these steels, i. e. to increase the depth www.intechopen.com Recrystallization 138 of drawing and avoid the crack during deep drawing process and at the same time to make the edge on the top of a drawn cup smooth without the phenomenon of earing, the deep drawing sheet is required to possess high plastic anisotropy, r m and low normal anisotropy, Δr. In other words, to maximize r m-value and minimize r-value, {111}<112> and {111}<110> components of -fiber (Figure 1) (Kestens et al., 1996) are the ideal crystallographic textures for deep drawing steel, because the correct texture gives the proper orientation of slip system so that the strength in the thickness direction is greater than that in the plane of the sheet. If {100} plane parallels rolling plane, the strength is lowest in the thickness direction of sheet. This, in turn, adversely influences the formability of the sheet. The {111}/{l00} intensity ratio is reported to be linearly related to r m (Held, 1965) and can easily be determined using X-ray diffractometer measurements of the (222) and (200) lines.
Materials Sciences and Applications, 2011
The role of magnesium (Mg) in improving the high temperature mechanical properties of the superal... more The role of magnesium (Mg) in improving the high temperature mechanical properties of the superalloys, like creep, fatigue, tensile ductility, impact toughness etc. have been vividly studied by several authors. On the other hand, very few authors have contradicted the view of any beneficial effect of Mg on the mechanical properties. This review presents a summary of the open literature related to the effect of Mg on the microstructure and mechanical properties of superalloys and from which further metallurgical research on the unexamined topics are proposed.
Metallurgical and Materials Transactions A, 2003
ABSTRACT HSLA-80 and HSLA-100 steels have been subjected to weld-simulated grain-coarsened heat-a... more ABSTRACT HSLA-80 and HSLA-100 steels have been subjected to weld-simulated grain-coarsened heat-affected zone (GCHAZ) and grain-refined heat-affected zone (GRHAZ) treatments at peak temperatures of 1350 C and 950 C, respectively, followed by varying cooling rates to approximate the weld heat inputs of 10 to 50 kJ/cm. Subsequent slow strain rate testing in synthetic seawater has been employed to assess the hydrogen embrittlement (HE) propensity of the materials. It is indicated that in spite of an increase in strength after weld simulation, further ductility deterioration, compared to the base material under similar testing conditions, did not occur in GCHAZ HSLA-100 steel and for low heat input condition of GRHAZ HSLA-80. This has been attributed to their HE resistant microstructures. Predominant acicular ferrite or lath martensite or a combination of both imparts resistance to HE, as observed in the case of grain-coarsened HSLA-100 and for the low heat input grain-refined HSLA-80 steels. The deleterious effect of bainitic-martensitic microstructure has been reflected in the ductility values of grain-coarsened HSLA-80, which is in agreement with the observation of higher susceptibility of the as-received HSLA-100 steel having a similar structure. However, contrary to its beneficial effect in the as-received HSLA-80, an acicular ferrite structure has shown vulnerability toward HE for high heat input grain-refined HSLA-80. This has been attributed to the presence of polygonal ferrite and to the development of an HE susceptible substructure on GRHAZ weld simulation.
British Corrosion Journal, 2000
ABSTRACT Hydrogen embrittlement behaviour of an HSLA–80 steel in the weld simulated, grain coarse... more ABSTRACT Hydrogen embrittlement behaviour of an HSLA–80 steel in the weld simulated, grain coarsened heat affected zone condition, in synthetic sea water under cathodic charging in the applied potential range of -600 to -1400 mV(SCE) has been studied using a slow strain rate technique. Loss of ductility, as reflected in the percentage elongation and percentage reduction in area values, was substantial at and beyond -800 mV(SCE). The material in the weld simulated condition showed more susceptibility than the as received material, which is considered to be a result of increased strength and a bainitic–martensitic microstructure. Fracture showed both microvoid coalescence and quasi-cleavage features and was indicative of hydrogen induced void nucleation. Both hardening and softening effects on hydrogen charging were experienced.
Nonisothermal austenite grain growth kinetics under the influence of several combinations of Nb, ... more Nonisothermal austenite grain growth kinetics under the influence of several combinations of Nb, Ti, and Mo containing complex precipitates has been studied in a microalloyed linepipe steel. The goal of this study is the development of a grain growth model to predict the austenite grain size in the weld heat affected zone (HAZ). Electron microscopy investigations of the as-received steel proved the presence of Ti-rich, Nb-rich, and Mo-rich precipitates. The steel has then been subjected to austenitizing heat treatments to selected peak temperatures at various heating rates that are typical for thermal cycles in the HAZ. Thermal cycles have a strong effect on the final austenite grain size. Using a mean field approach, a model is proposed for the dissolution of Nb-rich precipitates. This model has been coupled to a Zener-type austenite grain growth model in the presence of pinning particles. This coupling leads to accurate prediction of the austenite grain size along the nonisothermal heating path simulating selected thermal profiles of the HAZ.
Scripta Materialia, 2001
... 2. EJ Czyryca, RE Link, RJ Wong, DA Aylor, TW Montemarano, and JP Gudas, Naval Eng. J. May, 6... more ... 2. EJ Czyryca, RE Link, RJ Wong, DA Aylor, TW Montemarano, and JP Gudas, Naval Eng. J. May, 63 (1990). 3. AD Wilson, J. Metals. ... 21. RC Frank, in Internal Stresses and Fatigue in Metals, ed. GM Rassweiler and WL Grube, p. 411, Elsevier, New York (1959). 22. ...
Metallurgical and Materials Transactions A, 2010
Nonisothermal austenite grain growth kinetics under the influence of several combinations of Nb, ... more Nonisothermal austenite grain growth kinetics under the influence of several combinations of Nb, Ti, and Mo containing complex precipitates has been studied in a microalloyed linepipe steel. The goal of this study is the development of a grain growth model to predict the austenite grain size in the weld heat affected zone (HAZ). Electron microscopy investigations of the as-received steel proved the presence of Ti-rich, Nb-rich, and Mo-rich precipitates. The steel has then been subjected to austenitizing heat treatments to selected peak temperatures at various heating rates that are typical for thermal cycles in the HAZ. Thermal cycles have a strong effect on the final austenite grain size. Using a mean field approach, a model is proposed for the dissolution of Nb-rich precipitates. This model has been coupled to a Zener-type austenite grain growth model in the presence of pinning particles. This coupling leads to accurate prediction of the austenite grain size along the nonisothermal heating path simulating selected thermal profiles of the HAZ.