含Cu-Cr微合金钢650℃回火时第二相析出强化的研究  

Study of the Second Phase Precipitation Hardening in a Cu-Cr-bearing Microalloyed Steel Tempered at 650 ℃

作　　者：王泽民[1] 陈荣 羊忆军[1] 张杏耀[1] 刘克家[1] 

机构地区：[1]上海应用技术学院材料科学与工程学院,上海201418 [2]上海汇众汽车制造有限公司,上海200122

出　　处：《上海应用技术学院学报（自然科学版）》2012年第4期266-269,共4页Journal of Shanghai Institute of Technology: Natural Science

摘　　要：将含Cu-Cr微合金钢930℃保温30min淬火至室温,随后650℃回火10min～10h。利用光学显微镜(OM)和透射电子显微镜(TEM)研究不同回火时间条件下,样品中组织演变和第二相析出行为。结果表明:回火过程中组织从马氏体和贝氏体逐渐向针状铁素体和多边形铁素体演变;硬度变化曲线上出现2个二次硬化峰值,分别为回火1h和4h时的硬化峰,前者是V和Mo的碳化物析出强化结果,后者是由富Cu相的析出强化所致,V和Mo的碳化物强化产生的硬度值增量大于富Cu相;Cr的碳化物在回火过程中析出长大速度较快,析出强化能力较弱。Abstract：Optical microscope （OM） and transmission electron microscopy （TEM） were applied to in- vestigate the microstructure and the second phase precipitation in a Cu-Cr-bearing microalloyed steel tempered at 650℃after solution treatment at 930 ℃ for 30 min. The results indicated that martensite and bainite evolved to acicular ferrite and polygonal ferrite gradually during the tempering process. Two hardness peaks appeared with the sample tempered for 1 h and 4 h, corresponding to the precipitation strengthening effect of the V-Mo contained carbide and the Cu-rich phase, with the hardness increment generated by the carbide higher than that by the Cu-rich phase. The Cr-contained carbide grew faster during the tempering process, so that the precipitation hardening ability was weak.

关 键 词：微合金钢 CU 回火 析出强化 碳化物 

分 类 号：TG156.5[金属学及工艺—热处理]