稀土对低碳高铌钢粗轧过程再结晶的影响

Effect of rare earth on the recrystallization of high Nb steel roughing process

为了研究微合金高强钢再结晶行为,使用Gleeble-1500D热模拟试验机模拟低碳高铌钢3道次粗轧过程,测定了真应力-真应变曲线,并用应力补偿法计算软化率;采用电感耦合等离子体原子发射光谱仪(ICP)测定了不同稀土含量下Nb的固溶量;采用激光共聚焦显微镜观察了低碳高铌钢的奥氏体原始组织,分析了稀土对低碳高铌钢再结晶的影响.结果表明:加入11×10^(-6)稀土镧就能使1,3道次再结晶软化率降低约50%,并且能提高低碳高铌钢原始奥氏体晶粒的均匀性,使钢中Nb固溶百分比提高了16%.

In order to study the recrystallization behavior of micro alloyed high strength steel, the Gleeble - 1500D thermal simulation testing machine was used to simulate three pass rolling process of high Nb steel, and the true stress-strain curves were determined. The stress compensation method was used to calculate the softening rate. The dissolution of Nb at different rare earth content was determined using inductively coupled plasma atomic emission spectrometry （ICP）. The mierostructure of austenite in low carbon high Nb steel was observed by using the laser scanning confocal microscope, and the effect of rare earth on the austenitizing behavior of low carbon high Nb steel was analyzed . The results show that the addition of 11 ×10^-6RE in mass fraction can reduce the recrystallization softening rate of 1 and 3 times by about 50%, and improve the uniformity of the original austenite grain of low carbon high Nb steel, which makes the percentage of Nb solid solution increased by 16%