长期高温使用后2.25Cr-1Mo钢焊接接头热影响区的蠕变损伤  

Creep Damage in Heat Affected Zone of 2.25Cr-1Mo Steel Welded Joint after Using under Long-Term High Temperature

作　　者：于涛[1] 施惠基[1] 

机构地区：[1]清华大学工程力学系,北京100084

出　　处：《机械工程材料》2011年第4期1-3,31,共4页Materials For Mechanical Engineering

基　　金：国家重点基础研究发展计划项目(2006CB605003)

摘　　要：对火力发电厂中在571℃使用约26万h后的2.25Cr-1Mo钢管焊接接头不同区域的显微组织进行了观察,重点对热影响区的蠕变损伤程度进行了分析。结果表明:该钢弯管焊接接头腹侧的热影响区主要为细晶组织,接近设计寿命时细晶区内蠕变孔洞面积占比约为0.8%,这可作为同种材料管道焊接接头蠕变失效的判据;细晶区内部还存在大量的MnS夹杂物,其附近多伴有孔洞和微裂纹,是影响焊接接头蠕变寿命的一个因素。In the current work, observation was performed on the microstructure of different regions on the welded joint of a 2.25Cr-lMo steel pipe that had been operating at 571℃ for about 260 000 h in a power plant. The creep damge in heat affected zone （HAZ） was mainly analyzed. The results show that the HAZ of welded joint intrades was mainly fine-grained structure. The creep cavity area in fine-grained zone was about 0. 8% when steel pipe approached the design life, which could be a criterion for the creep failure of welded joints made of the same material. There were many MnS inclusions inside the fine-grained zone accompanied by cavities and microcracks, which was a factor of affecting the creep life of the welded joint.

关 键 词：蠕变 孔洞 焊接接头 热影响区 2.25CR-1MO钢 

分 类 号：TN304.8[电子电信—物理电子学]