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    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 Ltd
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    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.
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    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.
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    Microstructural Changes in Hypoeutectic Al�Si Alloys by Low Shear and Vibration Induced Melt Conditioning Setup
    (2018) Jha S.; Aditya G.S.L.; Mandal A.; Dhindaw B.K.
    In the present work, refinement of microstructure in hypoeutectic Al�Si alloys, i.e., A356 and Al�7wt%Si has been reported. One of the mechanical technique, melt conditioning, was used to refine the microstructure. The technique involved subjecting the melt to low shear force by passing it through a slope at a temperature above its liquidus temperature. In addition to the shear force, vibration was induced into the melt during its flow by a simple setup for melt conditioning. Shear force along with vibrations led to enhanced refinement in both the alloys, the most prominent being A356 alloy. It has been suggested that higher fraction of fragmented oxide particles/films into the molten A356 alloy during the flow before solidification in the mould could enhance the nucleation centres. It was concluded that the bi-oxides such as MgAlO4 acted as effective heterogeneous nucleants for ?-Al. � 2018, The Indian Institute of Metals - IIM.
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    From "grain refiners" to "aluminium based in-situ composites" in ternary Al-Ti-B system
    (2014) Chakraborty M.
    There has been a considerable interest in the ternary Al-Ti-B system amongst the aluminium casting fraternity. Of the many techniques used to synthesize grain refiners based on Al-Ti-B system, addition of halide salts - K2TiF6 and KBF4 - to molten aluminium has been one of the widely accepted routes. The present talk deals with the journey from the "development of grain refiners for aluminium alloys" to "aluminium based in-situ composites" in authors' laboratory over the last two decades. The concept of aluminium based in-situ composites reinforced with titanium diboride particles, which is an offshoot of the technique used to produce commercial grain refiners for aluminium alloys using halide salts, will be presented. The talk also discusses few challenges and opportunities in ternary Al-Ti-B system. Copyright � 2014 MS&T14�.