Effects of austenitizing temperature on the kinetics of the proeutectoid ferrite reaction at constant austenite grain size in an Fe-C alloy

1977 ◽  
Vol 8 (12) ◽  
pp. 1955-1961 ◽  
Author(s):  
J. R. Bradley ◽  
H. I. Aaronson ◽  
K. C. Russell ◽  
W. C. Johnson
Keyword(s):  
Grain Size ◽  
Austenitizing Temperature ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
Proeutectoid Ferrite ◽  
Kinetics Of

Effect of Austenitizing Temperature on the Quenching Microstructure and Properties of 51CrV4

2019 ◽  
Vol 944 ◽  
pp. 357-363
Author(s):  
Xiao Dong Zhang ◽  
Dian Xiu Xia ◽  
Shou Ren Wang
Keyword(s):  
Grain Size ◽  
Austenitizing Temperature ◽  
Austenite Grain Size ◽  
Microstructure And Properties ◽  
Austenite Grain ◽  
Test Steel ◽  
Austenite Grains ◽  
Martensite Structure

The effect of austenitizing temperature on the quenching microstructure and properties of 51CrV4 steel was studied. The results show that with the increase of austenitizing temperature, the austenite grains grow gradually. After quenching, the hardness increased first and then decreased, and the strength increased first and then decreased after tempering at 460°C. When the austenitizing temperature was 880°C, the austenite grains were fine and uniform, about 16μm, the martensite structure was dense, the strength and hardness reached maximum. When the austenitizing temperature was 910°C, the decarburization phenomenon was obvious, and the strength, hardness and plasticity of the test steel decreased obviously. When the austenitizing temperature exceeded 910°C, the austenite grains grow sharply and some grains were abnormally coarse. The austenite grain size reached 20μm and the microstructure was coarser at austenitizing temperature of 950°C. Therefore, in order to ensure uniform grain size and no decarburization under the premise of complete austenitization, the best austenitizing temperature of 51CrV4 steel for good properties is 880°C.

The Influence of Increased Cr Content and Austenite Grain Size on the Kinetics of Phase Transformations when Cooling Hypo-Eutectoid Steel

2006 ◽  
Vol 258-260 ◽  
pp. 421-426
Author(s):  
Ignacy Wierszyłłowski
Keyword(s):  
Activation Energy ◽  
Grain Size ◽  
Carbon Steel ◽  
Phase Transformations ◽  
Austenite Phase ◽  
Eutectoid Steel ◽  
Austenite Grain Size ◽  
Cr Content ◽  
Austenite Grain ◽  
Kinetics Of

The paper presents the influence of the grain size and a little higher Cr content on the kinetics of austenite phase transformations during continuous cooling of hypo-eutectoid steel. The kinetics of austenite phase transformations during continuous cooling were determined by means of analysis of the dilatometric curves and structure investigations. The influence of the austenite grain size and the higher Cr content was analysed in two hypoeutectoid steels containing about 0.4% C. One of them had, Cr content higher, by about 1%. In both steels, the austenite grain size was changing insignificantly up to the austenitising temperature of about 950fl. Above that temperature, the austenite grain size in carbon steel grew much quicker than that in the steel with Cr addition. The austenite grain in the Cr enriched steel was smaller than that in carbon steel and, in spite of that, the duration of cooled austenite transformations were several times longer. This means that the phase transformations are much more strongly influenced by the addition of chromium slowing down carbon diffusion in austenite, than by the austenite grain size. For each phase transformation in the examined steels, the activation energy of the transformation has been determined. The activation energy of all the phase transformations varied slightly with the increase of austenitising temperature. On the basis of the obtained results, curves of true isothermal transformations have been developed for the beginning of the phase transformations in both steels, related to infinitely quick cooling down to the transformation temperature.

Mesoscopic Simulation of the Ferrite Nucleation on Austenitic Grain Boundary for Nanograined Steel

2015 ◽  
Vol 817 ◽  
pp. 731-735
Author(s):  
Peng Yu ◽  
Lin Zhang ◽  
Lin Xiu Du ◽  
Jun Hu
Keyword(s):  
Grain Size ◽  
Phase Transformation ◽  
Nucleation Process ◽  
Austenite Grain Size ◽  
Mesoscopic Simulation ◽  
Thermodynamics And Kinetics ◽  
Austenite Grain ◽  
Austenite Grains ◽  
Ferrite Nucleation ◽  
Kinetics Of

We use the cellular automaton (CA) modeling to investigate the ferrite nucleation on the austenite grains. On the basis of the thermodynamics and kinetics of phase transformation from austenite to ferrite, the CA modeling demonstrates that the size of nucleated ferrite grains is increased with increasing of cooling rates, and nucleation process is finished instantly at a given cooling rate. The initial austenite grain size plays an important role in the obtained ferrite nucleation number, and the potential nucleation cells are increased.

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