稀土对高Nb钢奥氏体晶粒长大行为影响

Influence of rare earth on Austenite grain growth behavior in high Nb steel

钢中奥氏体晶粒越细小,经过组织转变后组织的力学性能越好.利用Gleeble-1500D热模拟机模拟稀土高Nb钢热处理过程,并对试样进行TEM观察与分析,研究稀土对加热时不同保温时间奥氏体晶粒大小的影响.结果表明:稀土能有效抑制加热过程中奥氏体晶粒长大,具有调整晶粒稳定性的作用,并且稀土降低沉淀相溶解的温度,促进第二相粒子在奥氏体中的溶解.

The comprehensive performance of the small Austenite grain becomes better after organization change in cooling process. The simulation of heat treatment of high Nb steel was carried out by the Gleeble - 1500D thermo-meehanieal experiment and the tested steel was studied using TEM to obtain the effect of rare earth on austenite grain size in different holding time. The results show that the rare earth can effectively inhibit the heating process of austenitie grain growth, and adjust with grain stability. In addition, the rare earth can reduce the precipitation dissolution temperature and promote the dissolution of 2nd-phase particles in Austenite.