不同冷却速率下X70管线钢铁素体相变的模拟  

Simulation of Ferrite Transformation With Different Cooling Rates for X70 Pipeline Steel

作　　者：赵彦峰[1] 王业勤 王晓南[1] 张殿华[1] 

机构地区：[1]东北大学轧制技术及连轧自动化国家重点实验室,辽宁沈阳110004 [2]山东莱芜钢铁股份公司生产处,山东莱芜271104

出　　处：《钢铁研究学报》2012年第2期54-58,共5页Journal of Iron and Steel Research

基　　金：国家重大基础研究发展规划项目(2006CB605208);教育部基本科研业务费项目研究生科研创新项目(N090607003)

摘　　要：为更精确地控制及优化X70管线钢的目标组织,以经典相变理论模型为基础,建立了先共析铁素体周围的临界碳浓度与原奥氏体的碳浓度之间的数学模型,并采用逆向回归法确定了铁素体相变分数的关键性参数,经试验验证,模型具有良好的精度。结果表明:临界碳浓度满足c*=1.8c0关系;铁素体相变分数的关键性参数m=1.3,b1=0.026,b2=-3.2;以冷速5℃/s为临界点,冷速对铁素体相变开始点的影响程度有明显变化;锰和铌含量对于铁素体相变开始温度的影响主要体现在α/γ界面处的溶质拖曳作用,铁素体相变开始温度由冷却速率和原始奥氏体晶界面积的乘积决定。In order to control and optimize microstructure of X70 pipeline steel more accurately, the mathematical model between critical carbon concentration around proeutectoid ferrite and original carbon concentration of austen ite was regressed based on classical phase transformation theory models. The key parameters of ferrite transformation were obtained by reversed regression method. It was confirmed that the model and the experimental result had a good agreement. It is shown that the critical carbon concentration agrees with a relational expression of c＊=1. 8c^0. The key parameters of ferrite transformation are as follows m=1.3, b1=0. 026, b2 = 3.2; the start tern perature of ferrite transformation has obvious effects on cooling rate when 5 ℃/s as critical point. The solute drag-like effect of α/γ interface is the main influence of composition of Mn and Nb on the start temperature of ferrite transfor mation. The start temperature of ferrite transformation is dominated by cooling rate and the area of austenite grain.

关 键 词：铁素体相变 冷却速率 X70管线钢 模拟 形核 

分 类 号：TG142.23[一般工业技术—材料科学与工程]