含微量稀土45钢的性能及组织研究_张秀芳.pdf

Hot Working Technology 2015,Vol.44,No.10 含微量稀土45 钢的性能及组织研究 秀芳 起兵 张 , 谭 （天 津 冶金 职 业技 术学院 冶金工程系 , 天 津 300400 ） 摘 要：研究了含有微量稀土的45 钢在不同热处理制度下的力学性能、组织形态以及断口形貌之间的关系。 结果 表明，亚温淬火后获得部分网状铁素体降低了实验钢的力学性能；在临界点以上进行淬火+ 回火处理，随淬火温度升高， 回火索氏体更加粗大，实验钢的强度略有提高，但塑性明显降低。 实验钢经800 ℃×15 min 水淬+550 ℃×90 min 回火后 具有最佳综合力学性能，而且组织均匀细小，拉伸断口以均匀细小的韧窝为主。 关键词： 钢； 稀土； 力学性能； 组织； 拉伸断口 45 DOI: 10.14158/j. cnki. 1001-3814. 2015. 10. 012 中图分类号： 文献标识码： 文章编号： TG156.3 A 1001-3814(2015)10-0046-02 Study on Properties and Microstructure of 45 Steel Containing Rare Earth ZHANG Xiufang, TAN Qibing (School of Materials Science and Metallurgical Engineering, Tianjin Metallurgical Vocation-technology Institute, Tianjin 300400, China) ： Abstract The relationship between properties, microstructure and fracture morphology of 45 steel containing rare earth after different heat treatment was investigated systematically. The results show that the mechanical properties of experimental steel reduce after intercritical heat treatment to obtain some reticular ferrite. When quenching temperature is higer than critical points, tempering sorbite is more thicker and the strength increases slightly, but the plasticity significantly decreases with the increase of quenching temperature. After quenching at 800 ℃ for 15 min, water cooling and then tempering at 550 ℃ for 90 min, the experimental steel has the best comprehensive mechanical properties and fine microstructure. The tensile fracture