改进型T23钢冲击韧度的改善  

Improvement in Impact Toughness of Modified T23 Steel

作　　者：柯志刚 朱丽慧[1] 周任远[1] 蓝凯 KE Zhigang;ZHU Lihui;ZHOU Renyuan;LAN Kai(School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China)

机构地区：[1]上海大学材料科学与工程学院,上海200444

出　　处：《上海金属》2022年第4期49-54,60,共7页Shanghai Metals

基　　金：国家重点研发计划(2016YFC0801901)。

摘　　要：改进型T23钢具有较低的再热裂纹敏感性,但其冲击韧度较差。为提高其冲击韧度,研究了正火冷却方式和回火温度对改进型T23钢组织和冲击韧度的影响。结果表明:改进型T23钢经1060℃保温60 min油冷+790℃回火90 min后冲击韧度和硬度得到提高,特别是冲击韧度提高到了276.6 J/cm2,为传统工艺热处理钢的37.4倍。相较于空冷正火的钢,油冷的改进型T23钢的硬度提高,冲击韧度大幅度提高。随着回火温度的升高,改进型T23钢的硬度下降,冲击韧度提高。经790℃回火后,钢中M-A岛大量分解,且晶界不连续分布的M23C6相能有效阻碍裂纹扩展,冲击韧度显著提高。Modified T23 steel has low susceptibility to reheat cracking,but poor impact toughness.In order to increase its impact toughness,the effects of normalizing cooling ways and tempering temperature on the microstructure and impact toughness of the modified T23 steel were investigated.The results showed that the impact toughness and hardness of the modified T23 steel were increased after normalizing at 1060℃for 60 min followed by oil cooling and tempering at 790℃for 90 min,especially the impact toughness was increased to 276.6 J/cm2,which was 37.4 times as higher as that of the steel heat treated by traditional procedure.Compared with the steel after normalizing followed by air cooling,the hardness and impact toughness of the modified T23 steel after normalizing followed by oil cooling were increased greatly.With the increase in tempering temperature,the hardness of the modified T23 steel decreased,whereas the impact toughness increased.After tempering at 790℃,a large amount of M-A islands were decomposed,and the discontinuously distributed M23C6 phases at grain boundaries could effectively prevent the propagation of cracks and significantly increase the impact toughness of the steel.

关 键 词：改进型T23钢 正火冷却方式 回火温度 M-A岛 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TG161[金属学及工艺—金属材料]