摘要
采用光学显微镜、扫描电镜研究了某厂X65Q/316L双金属复合管堆焊过渡区的组织和主要元素的分布情况,同时对过渡区显微硬度、拉伸强度、剪切强度进行了检测。结果表明:远离过渡区的X65Q基管组织为粒状贝氏体和珠光体,靠近熔合线处的基管组织为多边形铁素体和珠光体,原有粒状贝氏体组织消失;远离过渡区的316L衬管组织为奥氏体,且晶粒存在滑移变形;靠近熔合线处衬管奥氏体组织中的滑移变形消失;堆焊层与基管熔合线附近元素分布变化明显,而堆焊层与衬管熔合线附近元素分布未出现明显变化;堆焊层与基管过渡区内,堆焊层内硬度较稳定;基管硬度从熔合线处开始逐渐增加到最大值后迅速降低,远离熔合线区域堆焊层硬度高于基管。堆焊层与衬管过渡区内,靠近熔合线处堆焊层和衬管均发生了软化,硬度最低值出现在衬管侧靠近熔合线处,远离熔合线区域堆焊层的硬度高于衬管。
The microstructure and elements distribution of surfacing transition region of X65Q/316L bimetal clad pipe were investigated by optical microscope and SEM, and the microhardness, tensile strength and shear strength of transition region were tested. The results show that the microstructure of base tube far from the transition zone is granular bainite and pearlite, and the microstructure of base tube near the fusion line is polygonal ferrite and pearlite, and origina; granular baimate disappears. The microstructure of liner tube far from the transition zone is austenite with slip lines in the grains, while the microstrcuture of liner tube near fusion line is austenite with no slip lines. The elements distribution near the fusion line of surfacing layer and base tube changes significantly, while slight changes of elements distribution occur near the fusion line of surfacing layer and liner tube. In transition region of surfacing layer and base tube, the hardness of surfacing layer remains stable, while the hardness of base tube increases gradually to the maximum value from the fusion line and then decreases quickly.The hardness of swrface layer farfrom the fusion line is higher than that of the bsae tube. In the transition region of surfacing layer and liner tube, the surfacing layer and liner tube near the fusion line and occur softening. The lowest hardness appears in the liner tube near the fusion line. The hardness of surfacing layer far from the fusion line is higher than that of liner tube.
出处
《热加工工艺》
CSCD
北大核心
2017年第11期54-57,共4页
Hot Working Technology
关键词
双金属复合管
基管
衬管
微观组织
力学性能
bimetal clad pipe
base tube
liner tube
microstructure
mechanical properties
