合金元素对曲轴用非调质钢奥氏体长大和组织细化的影响  

Effect of alloying elements on austenite grain growth and microstructure refinement in a non-quenched steel for crankshafts

作　　者：张朝磊[1] 杨忠[1,2] 孙景宏[1] 赵海东 李柏远 刘雅政[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]西宁特殊钢集团有限责任公司,西宁810005

出　　处：《工程科学学报》2015年第2期175-179,共5页Chinese Journal of Engineering

摘　　要：通过研究曲轴用非调质钢奥氏体晶粒长大行为和分析工业生产热轧材的显微组织,探讨合金元素Nb、Ti和S的组织细化作用.结果表明:添加质量分数0.027%Nb和0.012%Ti,同时S从0.029%提高到0.046%,加热时间30 min时,能够把奥氏体晶粒粗化温度提高100℃,并明显细化热轧材边部组织.弥散分布、钉扎在奥氏体晶界上的未溶第二相粒子Mn S和(Nb,Ti)(C,N),能够有效抑制奥氏体晶粒的长大.在热加工过程中,合金元素的组织细化作用需要适当的变形制度予以匹配,才能得以体现.The microstructural refinement effect of alloying elements Nb, Ti and S was investigated by analyzing austenite grain growth behavior and hot-rolled microstructure in a non-quenched steel for crankshafts. The results show that the austenite grain coarse- ning temperature increases by 100℃ when the heating time is 30 min, and the microstructure in the hot-rolled bar edge is significantly refined after 0. 027% Nb-0. 012% Ti microalloying and an increase of S from 0. 029% to 0. 046% in the steel investigated. The undissolved second phase particles MnS and （ Nb, Ti） （ C, N） have a pinning effect on austenite grain boundaries, and then retard the austenite grain growth. Besides, the microstructural refinement effect of the alloying elements needs a suitable deformation schedule.

关 键 词：钢合金化 合金元素 奥氏体 晶粒长大 组织细化 曲轴 

分 类 号：TG142.1[一般工业技术—材料科学与工程]