TY - JOUR
T1 - Carbide Precipitation Behavior of High-Alloy Steel During Solidification and Cooling Process
AU - He, Shuai
AU - Li, Zhi Feng
AU - Liu, Xin
AU - Liu, Xu Ming
AU - Zhang, Chi
AU - Wang, Jun Sheng
N1 - Publisher Copyright:
© 2024 Wiley-VCH GmbH.
PY - 2024/8
Y1 - 2024/8
N2 - The precipitation, growth, and transformation of carbides rich in Cr and Mo during solidification and cooling process of high-alloy steel for cold working dies are investigated. The Fe–C pseudobinary phase diagram of high-alloy steel is calculated by Thermo-Calc software to ascertain the critical phase transformation temperatures. The temperatures of phase transformation during the solidification process are determined by a differential scanning calorimeter. Then the microstructure of the samples at these characteristic temperatures is observed in situ by high-temperature confocal microscope. The results show that the characteristic temperatures for phase transformation and carbide precipitation are 1380, 1315, 1140, and 980 °C, respectively. At 1315 °C, thick rod-like or island-like M7C3 carbides enriched in Cr and Fe are formed. At 1140 °C, secondary M7C3, adhering to the primary eutectic M7C3, grows rapidly in a rod-like morphology and maintains a similar composition. The secondary M6C carbides of segregated Mo elements precipitate in fan-shaped clusters near M7C3 through the dissolution of M7C3 and the conversion of M2C. Thermodynamic calculation further indicates that the eutectic Cr7C3 precipitates at 1213 °C, and secondary Cr7C3 remains under conditions favorable for precipitation below the solidus, preceding the precipitation of secondary carbides Cr23C6 and Mo2C.
AB - The precipitation, growth, and transformation of carbides rich in Cr and Mo during solidification and cooling process of high-alloy steel for cold working dies are investigated. The Fe–C pseudobinary phase diagram of high-alloy steel is calculated by Thermo-Calc software to ascertain the critical phase transformation temperatures. The temperatures of phase transformation during the solidification process are determined by a differential scanning calorimeter. Then the microstructure of the samples at these characteristic temperatures is observed in situ by high-temperature confocal microscope. The results show that the characteristic temperatures for phase transformation and carbide precipitation are 1380, 1315, 1140, and 980 °C, respectively. At 1315 °C, thick rod-like or island-like M7C3 carbides enriched in Cr and Fe are formed. At 1140 °C, secondary M7C3, adhering to the primary eutectic M7C3, grows rapidly in a rod-like morphology and maintains a similar composition. The secondary M6C carbides of segregated Mo elements precipitate in fan-shaped clusters near M7C3 through the dissolution of M7C3 and the conversion of M2C. Thermodynamic calculation further indicates that the eutectic Cr7C3 precipitates at 1213 °C, and secondary Cr7C3 remains under conditions favorable for precipitation below the solidus, preceding the precipitation of secondary carbides Cr23C6 and Mo2C.
KW - carbide precipitation
KW - characteristic temperature
KW - high-alloy steels
KW - solidification
KW - thermodynamic calculation
UR - http://www.scopus.com/inward/record.url?scp=85194580449&partnerID=8YFLogxK
U2 - 10.1002/srin.202400130
DO - 10.1002/srin.202400130
M3 - Article
AN - SCOPUS:85194580449
SN - 1611-3683
VL - 95
JO - Steel Research International
JF - Steel Research International
IS - 8
M1 - 2400130
ER -