终冷温度对低屈强比高强钢组织和性能的影响  

Influence of finish cooling temperature on microstructure and mechanical properties of high strength steel with low yield ratio

作　　者：童明伟[1,2] 袁泽喜[1] 张开广[2] 范巍[2] 

机构地区：[1]武汉科技大学材料与冶金学院,湖北武汉430081 [2]武汉钢铁(集团)公司研究院,湖北武汉430080

出　　处：《金属热处理》2016年第6期97-100,共4页Heat Treatment of Metals

基　　金：国家"十二五"科技支撑计划项目(2012BAJ13B01)

摘　　要：采用力学性能测试、光学显微镜、透射电镜等方法,研究了终冷温度对低屈强比高强钢组织和性能的影响。结果表明,随着终冷温度的降低,钢的屈服强度和抗拉强度增加,伸长率下降,而屈强比和冲击吸收能量则没有明显的变化,但总体呈现出下降趋势。试验钢的组织主要由板条贝氏体、粒状贝氏体、少量铁素体和一些M/A岛组成,终冷温度越低,板条贝氏体宽度越窄,铁素体组织也更加细小。M/A岛体积分数的增加有利于提高强度和降低屈强比,但对冲击性能不利。Influence of finish cooling temperature on microstructure and mechanical properties of high strength steel with low yield ratio was analyzed by means of mechanical property test and microstructural analysis with optical microscope and transmission electron microscopy. The results show that both the yield strength and tensile strength of the steel increase, and the elongation decreases with decreasing of finish cooling temperature, while the yield ratio and the impact toughness of the steel change unregularly. The microstructure of the steel is composed of fine lath bainite, small fraction of ferrite and some M/A island. The lower the finish cooling temperature is, the thinner the lath width of bainite is, and the size of ferrite is finner too. Increasing the fraction of M/A constituent can improve the strength and reduce the yield ratio of the steel, but deteriorates the toughness.

关 键 词：低屈强比高强钢 终冷温度 微观组织 力学性能 

分 类 号：TG156.4[金属学及工艺—热处理] TG142.1[金属学及工艺—金属学]