Ti-Mo微合金钢回火过程中纳米碳化物析出行为  

Precipitation of nanoscale carbides in Ti-Mo microalloyed steel during tempering process

作　　者：卜凡征 王玉斌 郑连辉 王学敏 吴庆美 郭强 BU Fan-zheng;WANG Yu-bin;ZHENG Lian-hui;WANG Xue-min;WU Qing-mei;GUO Qiang(TKAS Auto Steel Company Limited,Dalian 116600,Liaoning,China;Collaborative Innovation Center of Steel Technology,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]鞍钢蒂森克虏伯汽车钢有限公司,辽宁大连116600 [2]北京科技大学钢铁共性技术协同创新中心,北京100083

出　　处：《钢铁研究学报》2018年第11期928-934,共7页Journal of Iron and Steel Research

摘　　要：利用透射电镜对含Ti微合金钢热轧及回火后的析出相分布、形貌和尺寸进行了观察和分析,结合拉伸试验结果研究了回火过程中纳米析出颗粒的变化特征及其对试验钢强度变化的影响。结果表明,600℃回火2h试验钢的屈服强度达到最大值,这是由于除了热轧后空冷形成的高体积分数相间析出以外,回火过程中又形成了大量的过饱和析出,此时纳米析出相体积分数较其他温度增加约3%~5%,颗粒平均尺寸为5~6nm,分布最均匀。随着回火温度的升高和回火时间的延长,2类析出颗粒均发生了不同程度的粗化,相间析出颗粒尺寸均在8nm以下,较过饱和析出颗粒具有较好的热稳定性,析出强化作用更明显。The distribution,morphology and size of the carbide precipitates in as-rolled and as-tempered Ti-Mo microalloyed steels were elucidated by optical microscopy and transmission electron microscopy.The change in nanoscale precipitate during tempering and its effect on strength of test steel were analyzed by tensile test.The resuits revealed that substantial improvement in yield strength occurred on tempering at 600℃ for 2h because of the supersaturated precipitation and homogeneous distribution of profuse (Ti,Mo)C carbide in the matrix in average size from 5-6nm except interpbase precipitation,and the precipitation volume fraction of the sample tempered at 600℃ exhibited an approximate 3%-50% increase compared to the samples tempered at 650and 700℃.With increase in tempering temperature and holding time,the interphase-precipitated carbides were observed to have slightly coarsened to a maximum size of less than 8nm,but did not coarsen as much as the supersaturated carbides formed during tempering.The interphase precipitation exhibits more excellent behavior of thermal stability than supersaturated precipitation during tempering process.

关 键 词：Ti-Mo微合金钢 屈服强度 相间析出 过饱和析出 回火稳定性 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TB383.1[金属学及工艺—金属材料]