层流冷却过程低碳钢相变模型的适用性分析

选取了现有典型的C-Mn钢相变过程的物理冶金模型,包括5组孕育期模型、7组相变动力学方程模型、5组相变后铁素体晶粒尺寸模型.利用自行开发的组织性能预报系统软件模拟计算了在3组实际冷却工艺条件下各模型的奥氏体转变过程,并对各模型进行了评价.结果表明,对于所设定的成分和工艺条件,适用性较好的孕育期模型是Kwon所提出的模型...

Applicability Assessment of Phase Transfromation Models of Low Carbon Steel in Laminar Flow Cooling Process

In this paper, available austenite phase transformation models of C-Mn steels were collected and compared to investigate their applicability. Five groups of incubation period models (according to Scheil’s additivity rule) were used to calculate ferrite transformation start temperature, seven groups of avrami equations were used to describe phase transformation kinetic process, and five groups of grain size models were used to predict ferrite grain size after transformation completion. By use of a developed integrated process modeling system in which thermal, mechanical and metallurgical processes from reheating furnace to coiling of a steel strip had been numerically and successfully coupled together. Phase transformation process was investigated under three different runout table cooling conditions (cooling rate is 10℃/s, 20℃/s and 40℃/s respectively) during hot strip rolling at 2050 HSM of Baosteel Co. Ltd. Applicability of phase transformation models were discussed by comparing the calculated data with experimental data. The results show that models proposed by Kwon are suitable for the incubation period; models of Avrami equations proposed by Liu, Donnay and Sun are suitable for the kinetics of phase transformation; and for the ferrite grain size, models proposed by Hodgson is suitable.