【作者】 胡杰； 姜志忠； 黄继华； 陈树海； 赵兴科； 张华；

【机构】 北京科技大学材料科学与工程学院；

【摘要】 对10mm厚聚变堆用中国低活化马氏体钢(CLAM钢)板进行了不同焊接热输入的真空电子束焊接试验,利用光学显微镜(OM)、扫描电镜(SEM)对焊缝显微组织进行了观察,观察显示焊缝组织由粗大板条马氏体和δ铁素体构成;对焊缝中δ铁素体含量利用染色法进行了精确地定量统计,结果显示随着焊接热输入由3.31kJ.cm-1增大至5.22 kJ.cm-1,焊缝内δ铁素体含量由10.74%减少至7.36%;通过CLAM钢的δ铁素体形成倾向性分析及热力学平衡相图的计算表明:CLAM钢本身具有的强δ铁素体稳定性及焊接的非平衡快速冷却过程的综合作用,导致了焊缝中δ铁素体的存在,其中成分是δ铁素体形成的决定性因素。更多还原

【Abstract】 China low activation martensitic(CLAM) steel with 10mm thickness used for fusion reactor was welded by various heat input vacuum electron beam welding processes.The characteristics of microstructure of the weld metals were investigated by optical microscope(OM),scanning electron microscope(SEM).Experimental results indicate that the microstructure of the weld metals is composed of coarse lath-shaped martensite with high content of delta-ferrite in as-welded condition.The quantitative statistics for the content of Delta-ferrite in the weld metals was done by staining method accurately.It shows that with the heat input increases from 3.31KJ.cm-1 to 5.22 KJ.cm-1,the content of delta-ferrite in weld metal decreases from 10.74% to 7.36%.Delta-ferrite formation tendency of CLAM steel was analysed and thermodynamic calculation of equilibrium phase was done,which indicates that the formation of delta-ferrite in weld metal is determined by two factors,the first is that CLAM steel has the strong delta ferrite stability,which is the decisive factor.Meanwhile,the second is that non-equilibrium cooling rates decided by welding process.更多还原