T23低合金耐热钢再热裂纹敏感性研究  

Study on Susceptibility of T23 Low-alloy Heat-resistant Steel to Reheat Cracking

作　　者：李世贤 朱丽慧[1] 周任远[1] 柯志刚 翟国丽 LI Shixian;ZHU Lihui;ZHOU Renyuan;KE Zhigang;ZHAI Guoli(School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China;Central Research Institute of Baosteel Group Corporation, Shanghai 201900, China)

机构地区：[1]上海大学材料科学与工程学院,上海200444 [2]宝钢集团中央研究院,上海201900

出　　处：《上海金属》2020年第3期7-11,共5页Shanghai Metals

基　　金：国家重点研发计划“典型材料和焊接接头的高温损伤机理及早期诊断关键技术研究”(No.2016YFC0801901)。

摘　　要：试制了4种改进型即改变了碳、钨、钼、铬和铌含量的T23低合金耐热钢。试验用钢经锻造和轧制后,进行了1060℃正火和770℃回火。检测了改进的T23钢和原T23钢的再热裂纹敏感性、拉伸性能和显微组织。结果表明:改进型T23钢的再热裂纹敏感性均小于原T23钢,并且其屈服强度、抗拉强度和断后伸长率均满足ASME要求。改进型T23钢中,含0.045%C、2.640%Cr、0.630%Mo、0.440%W和0.020%Nb(质量分数)的D钢的再热裂纹敏感性最小,屈服强度和抗拉强度最高,分别为637和720 MPa。碳、铬、钨、钼和铌改善T23钢的再热裂纹敏感性的机制为:这些元素影响晶内MX析出相的数量、晶内的固溶强化以及晶界M23C6析出相的数量,从而改变晶内、晶界的强度差进而影响再热裂纹敏感性。Four types of modified T23 low-alloy heat-resistant steels with different contents of carbon,tungsten,molybdenum,chromium and niobium were trial-produced,forged and rolled,then normalized at 1060℃and tempered at 770℃.The modified and the original T23 steels were tested for susceptibility to reheat cracking,tensile properties and microstructure.The results showed that the modified T23 steels were less susceptible to reheat cracking than the original T23 steel,and exhibited yield strength,tensile strength and elongation which satisfied ASME requirements.Of the modified T23 steels,steel D containing 0.045%C,2.640%Cr,0.630%Mo,0.440%W and 0.020%Nb(by mass)showed the least susceptibility to reheat cracking,and the highest yield strength and tensile strength of 637 MPa and 720 MPa,respectively.The mechanism whereby the susceptibility of T23 steel to reheat cracking was improved was that these elements exerted an influence on the amount of MX precipitates in the grain interiors,the solid solution strengthening of the grain interiors and the amount of M23C6 precipitates at the grain boundaries,thereby changed difference between the intragranular strength and the intergranular strength,and then proceeded to exerted an influence on the susceptibility to reheat cracking.

关 键 词：T23钢 再热裂纹敏感性 成分优化 

分 类 号：TG1[金属学及工艺—金属学]