聚变堆用CLAM钢电子束焊接接头显微组织转变与力学性能  

Microstructure transformation and mechanical properties of electron beam welded joints of fusion CLAM steel

作　　者：姜志忠[1] 黄继华[1] 陈树海[1] 巨新[2] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]北京科技大学应用科学学院,北京100083

出　　处：《焊接学报》2011年第3期45-48,115,共4页Transactions of The China Welding Institution

基　　金：国家重点基础研究发展规划项目(2008CB717802)

摘　　要：对聚变堆用CLAM钢进行了真空电子束焊接试验,并在740℃/1 h条件下对接头进行焊后热处理,利用金相显微镜和显微硬度计对接头各区域热处理前后显微组织转变及硬度分布进行了研究.结果表明,焊缝成形良好,无不良外观缺陷;焊态焊缝和熔合区由粗大板条马氏体+少量δ铁素体组成,硬度大于410 HV.完全淬火区粗晶区由粗大板条马氏体组成,细晶区由细小板条马氏体组成,细晶区是焊接接头硬度最高的区域.不完全淬火区由细小板条马氏体+铁素体组成.接头不存在软化区;焊后热处理使接头中的马氏体转变为回火索氏体组织,各区域硬度明显下降,其中,熔合区的硬度最高,仅比基体母材硬度高20%左右,热处理并没有使接头出现明显的软化现象.China low activation martensitic(CLAM) steel for fusion reactor were butt-welded through electron beam welding process,and followed by post-welding heat treatment(PWHT) at 740 ℃ for 1 h.The microstructure and microhardness distribution of welded joints were analysed.The results showed that the weld seam with good formation and without appearance defects has been achieved.In as-welded condition,the weld metal and fusion zone consisted of a mixture of coarse lath martensite and a little δ ferrite.The coarse and fine grained zone was composed of fine lath martensite.The partially quenched zone mainly consisted of fine lath martensite and ferrite.The softening did not occur across welded joint.After PWHT,the lath martensite in the welded joint was transformed into tempered sorbite,which led to the significant decrease of the hardness of each zone.Among them,the highest hardness emerges at fusion zone was not at fine grained zone,which was just 20% higher than base metal.The PWHT did not make the tempered zone and base metal more soft obviously.

关 键 词：中国低活化马氏体钢 电子束焊接 金相组织 显微硬度 

分 类 号：TG457.11[金属学及工艺—焊接]