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Item Corrosion behavior of heat-treated and cryorolled Al 5052 alloys in different chloride ion concentrations(2020) Abu Seman A.; Chan J.K.; Norazman M.A.; Hussain Z.; Brij D.; Ismail A.Purpose: This paper aims to investigate the corrosion behaviour of heat-treated and cryorolled Al 5052 alloys in different Cl? ion concentrations. Design/methodology/approach: NaCl solutions with concentrations of 0, 0.5, 3.5 and 5.5 per cent were selected. Samples were subjected to pre-heat treatment (annealing at 300 �C and solution treatment at 540 �C) and cryorolling up to 30 per cent reduction before undergoing corrosion tests. The corrosion behaviour of the samples was then investigated by potentiodynamic polarization. The microstructure of the corroded samples was evaluated under an optical microscope, and the percentages of pits on their surfaces were calculated. Findings: The cryorolled samples had a lower corrosion rate than the samples that were not cryorolled. The cryorolled sample that underwent solution treatment showed the highest corrosion resistance among all the samples tested. Practical implications: The commercial impact of the study is the possibility of using the cryorolled Al alloy in various ion chloride environment. Originality/value: The obtained results help in understanding the corrosion behaviour of cryorolled samples under different heat treatment conditions. � 2019, Emerald Publishing Limited.Item Corrosion behavior of heat-treated and cryorolled Al 5052 alloys in different chloride ion concentrations(2019) Abu Seman A.; Chan J.K.; Norazman M.A.; Hussain Z.; Brij D.; Ismail A.Purpose: This paper aims to investigate the corrosion behaviour of heat-treated and cryorolled Al 5052 alloys in different Cl? ion concentrations. Design/methodology/approach: NaCl solutions with concentrations of 0, 0.5, 3.5 and 5.5 per cent were selected. Samples were subjected to pre-heat treatment (annealing at 300 �C and solution treatment at 540 �C) and cryorolling up to 30 per cent reduction before undergoing corrosion tests. The corrosion behaviour of the samples was then investigated by potentiodynamic polarization. The microstructure of the corroded samples was evaluated under an optical microscope, and the percentages of pits on their surfaces were calculated. Findings: The cryorolled samples had a lower corrosion rate than the samples that were not cryorolled. The cryorolled sample that underwent solution treatment showed the highest corrosion resistance among all the samples tested. Practical implications: The commercial impact of the study is the possibility of using the cryorolled Al alloy in various ion chloride environment. Originality/value: The obtained results help in understanding the corrosion behaviour of cryorolled samples under different heat treatment conditions. � 2019, Emerald Publishing Limited.Item Study on effect of double austenitization treatment on fracture morphology tensile tested nuclear grade P92 steel(2019) Pandey C.; Mahapatra M.M.; Kumar P.; Kumar P.; Saini N.; Thakare J.G.; Kumar S.Effect of �conventional normalizing and tempering� (CNT) and �double austenitization based normalizing and tempering� (DNT) process on microstructure characteristic and mechanical behavior was studied forP92 steel. In CNT heat treatment, P92 steel is normalized at 1040 �C/air cool and tempered with 760 �C/2 h/air cool. In DNT heat treatment, initially normalizing was performed at 1040 �C for 1 h followed by water quenching. After that sample was normalized in the temperature range of 950�1150 �C for 1 h and tempered at 760 �C/2 h/air cool (950 �C-DNT1, 1050 �C-DNT2, 1150 �C-DNT3).Grain size for CNT and DNT1 treatment were measured 17 � 7 ?m and 12 � 5 ?m. A DNT treatment resulted in homogeneous microstructure formation that led to improved mechanical properties as compared to CNT treatment. The DN based heat treatment produced complete martensitic microstructure formation by complete dissolution of carbide precipitates. The optimized room temperature condition was obtained for the DNT 1 heat treatment. � 2018 Elsevier LtdItem Role of Heat Treatment on Grain Refinement and Microhardness of 9Cr�1Mo�V�Nb Steel(2019) Pandey C.; Sirohi S.; Mahapatra M.M.; Kumar P.; Bansal K.K.Effect of �double austenitizing� (DN) on microstructure evolution and mechanical properties of martensitic 9Cr�1Mo�V�Nb (P91) steel were studied and compared with the �conventional normalizing� (CN) process. In CN treatment, P91 steel is normalized at 1050��C for 1�h, finally air cooled. In DN treatment, the first stage of normalizing was performed at 1050��C/1�h/air cool. The second stage of normalizing was performed in the temperature range of 950�1150��C for 1�h (950��C-DN1, 1050��C-DN2, 1150��C-DN3), followed by water quenching. The grain size was measured 42 and 35��m for CN and DN1 treatment, respectively. The double normalizing (DN) produced complete martensitic microstructure as a result of complete dissolution of precipitates. In DN-based heat treatment, optimized microstructure and mechanical properties were obtained for the sample that normalized at 950��C, followed by water quenching. � 2019, ASM International.Item Grain refinement of P91 steel using double austenitization treatment(2018) Pandey C.; Mahapatra M.M.; Kumar P.; Saini N.; Thakre J.G.; Kumar P.The effect of conventional normalizing and tempering (CNT) and double austenitization-based normalizing and tempering (DNT) heat treatments on the microstructure evolution and mechanical properties of creep strength-enhanced ferritic P91 steel were studied. CNT treatment was performed at 1,050�C and air cooled for 1 h and also at 760�C and air cooled for 2 h. In double austenitization- based normalizing heat treatment, steel was austenitized at 1,050�C and air cooled for 1 h and then normalized in a temperature range of 950�C -1,150�C for 1 h followed by water quenching. After the double normalizing, tempering is performed at 760�C for 2 h. A DNT treatment resulted in homogeneous microstructure formation that led to improved mechanical properties as compared to CNT treatment. The incomplete dissolution of precipitates in single-stage tempering resulted in incomplete martensitic structure formation. � 2018 by ASTM International.Item Influence of in situ TiB reinforcements and role of heat treatment on mechanical properties and biocompatibility of ? Ti-alloys(2012) Majumdar P.; Singh S.B.; Dhara S.; Chakraborty M.The effect of heat treatment on the mechanical properties of Ti-35Nb-5.7Ta-7.2Zr (TNZT) and Ti-35Nb-5.7Ta-7.2Zr-0.5B (TNZTB) alloys has been investigated. In the case of TNZT alloy, the presence of ? phase in the matrix has a greater effect on strength and hardness than the presence of secondary ? precipitates. The TNZTB alloy shows higher hardness and tensile strength than the TNZT alloy due to the formation of hard TiB precipitates in the matrix of the former. However, the boron free alloy offers higher ductility than the boron containing alloy. Presence of TiB precipitates in the matrix increases the strength of the TNZTB alloy when ? precipitates are present in the matrix. However, the boride precipitates have no substantial influence on the strength of the TNZTB alloy when ? phase in the matrix is replaced by the ? phase. The elastic modulus of the TNZT samples shows a very small variation with different heat treatment conditions. The TNZT alloy samples containing ? and ? phases show higher elastic modulus than the samples containing ? and ? phases. The elastic modulus of the TNZTB alloy is higher than that of the TNZT alloy due to the formation of high modulus TiB particles in the matrix. Both the alloys show better cell adhesion and spreading than the control material (polystyrene). However, the boron free Ti-alloy shows better cell attachment than the boron containing Ti-alloy. � 2012 Elsevier Ltd.Item Effects of heat treatment on evolution of microstructure of boron free and boron containing biomedical Ti-13Zr-13Nb alloys(2012) Majumdar P.In the present study, the effects of heat treatment on the microstructure of Ti-13Zr-13Nb (TZN) and Ti-13Zr-13Nb-0.5B (TZNB) alloys have been investigated. Depending on the heat treatment conditions, the microstructure of the heat treated TZN alloy consisted mainly of elongated and/or equiaxed ?, ? or martensite. Slow cooling (furnace or air cooling) from the solution treatment temperature produced ? and ? phases in the microstructure. Rapid cooling (water quenching) resulted in martensite and retained ? when the solution treatment temperature was above or close to ? transus. However, martensite was not formed after water quenching from a solution treatment temperature which was below ? transus due to partitioning effect of the alloying elements. Increasing the cooling rate from the furnace cooling to the air cooling led to finer microstructure. Aging of water quenched samples transformed the martensite, if present, into ? and ?, and the morphology of ? phase changed from elongated to equiaxed and enhanced the growth of ?. The microstructure of all the TZNB samples consisted of dispersed precipitated particles of TiB in the matrix. The majority of the boride particles showed an acicular (needle like) morphology. The other phases present in the TZNB alloy were similar to those in the similarly heat treated TZN alloy. Moreover, a growth of ? phase was observed in the microstructure of TZNB alloy when compared with that of TZN alloy. � 2012 Elsevier Ltd.Item Effect of heat treatment and boron addition on corrosion behavior of Ti-35Nb-7.2Zr-5.7Ta (wt%) ?-titanium alloy in simulated body fluid(2011) Majumdar P.; Singh S.B.; Chatterjee U.K.; Chakraborty M.The corrosion behavior of Ti-35Nb-7.2Zr-5.7Ta (TNZT) and Ti-35Nb-7.2Zr-5.7Ta-0.5B (TNZTB) alloys subjected to different heat treatment conditions was investigated in Hank's solution. Depending on the heat treatment conditions, the microstructure of the water-quenched, single-stage aged or duplex aged samples consists of very small amounts of ? or a precipitates in equiaxed � grains. Addition of boron to the TNZT alloy results in the formation of dispersed precipitates of titanium boride (TiB) in the � matrix. The other features present in the TNZTB alloy are similar to those in the TNZT alloy. Compared with single aging, duplex aging decreases the corrosion potential (Ecorr) and substantially decreases corrosion current density (icorr) and passive current density (ipass) values. Addition of boron to the TNZT alloy shifts the Ecorr value toward a more active direction and increases the icorr as well as ipass values significantly, and therefore deteriorates the corrosion resistance of the titanium alloys. In general, duplex aged TNZT samples show better corrosion resistance than other heattreated TNZT or TNZTB samples. � 2011, NACE International.Item The influence of heat treatment and role of boron on sliding wear behaviour of β-type Ti-35Nb-7.2Zr-5.7Ta alloy in dry condition and in simulated body fluids(2011) Majumdar P.; Singh S.B.; Chakraborty M.The wear behaviour of heat-treated Ti-35Nb-7.2Zr-5.7Ta (TNZT) and Ti-35Nb-7.2Zr-5.7Ta-0.5B (TNZTB) alloys (all compositions are in wt%) was investigated in dry condition and in simulated body fluids. It has been found that there is no straightforward relationship between the wear rate and the microstructure. The hardness has no appreciable effect on the wear behaviour of these alloys. The presence of boron in the TNZT alloy deteriorates its wear properties. The wear rate of TNZT and TNZTB alloys in various media increases in the following sequence: dry condition < Hank's solution < bovine serum. © 2010 Elsevier Ltd.