摘要
通过对一服役１０＾５ｈ的Ｃｒ５Ｍｏ工艺管线异质焊接接头的力学性能，焊缝界面组织变化，碳扩散和热应力的测试分析，发现异质焊接接头的焊接过程中存在一些焊接缺陷，如未熔合，夹渣等，其中未熔合深度达壁厚的２／３，但这些缺隐在服役过程中并未扩展，主要原因是管线中应力水平较低，母材与焊缝组织是正常的，焊缝熔点线处应力最高；焊接熔合区存碳迁移，因此焊接熔合区是薄弱环节，应加强监控，综合上述分析结果。
In this paper, the microstructure and mechanical properties of Cr5Mo pipeline joints welded with dissimilar material, which have been put into service under high temperature for 10,0000 hours, are analyzed by means of optical microscope, scanning electron microscope and finite element method. The results show that the migration of carbon takes place and decarburization layer is formed in the bond. In the other hand, stress concentration is caused in the bond due to difference of thermal expansion coefficient between Cr5Mo steel and austenitic weldmet-al. Therefore, the bond is the weak link. Lack of fusion and slag inclusion were found in the welded joint. Tests have proved that these defects were not formed during.service of the pipeline, but in the welding process. Tests also show that these cracks didn't propagate after long-time service under elevated temperature because of its lower stress level. It is concluded that the most important parameters affecting the fracture strength of dissimilar weld-ment are the migration of carbon and thermal stress at the interface.
出处
《理化检验（物理分册）》
CAS
1998年第12期12-16,共5页
Physical Testing and Chemical Analysis(Part A:Physical Testing)
关键词
延寿分析
异质
焊接接头
碳迁移
应力
高温
临氢
Remaining life analysis Dissimilar metal weldment joint Migration of carbon Thermal stress
