UOE钢管焊接接头CTOD断裂韧性评定方法(英文)  

CTOD Testing and Evaluation for Weld Joint of UOE Pipeline Steel

作　　者：苗婷[1] 苗张木[1] 刘硕[2] 曹能[2] 马朝晖[2] 

机构地区：[1]武汉理工大学交通学院,武汉430063 [2]宝山钢铁股份有限公司研究院(技术中心),上海201900

出　　处：《船舶力学》2012年第12期1468-1478,共11页Journal of Ship Mechanics

摘　　要：根据英国标准BS7448,对UOE直缝埋弧焊管不同钢级管线钢焊接接头进行裂纹尖端张开位移(CTOD)断裂韧度测试。结合加拿大标准CSA Z662-07及挪威船级社规范NDV-OS-F101,在试样形式选择、缺口取样方向、后期金相检验等方面对断裂韧性评定方法加以完善。试验结果表明X70、X65级管线钢均具有良好韧性,符合规范NDV-OS-F101的要求。X70级管线钢焊接接头各区域韧性分布规律为:母材性能最好,焊缝次之,热影响区(HAZ)相对较差。X65级管线钢其HAZ的韧性优于母材和焊缝。其原因是:X65 级钢母材含有一定气孔、夹杂,断口出现分层裂纹,导致CTOD结果分散性大。另外,X65焊缝组织为混晶组织分布不均,含有大量M-A脆性组织物,导致韧性下降。该评定结果为海底管线钢制造工艺改进提供了依据,也为海洋工程结构安全性评估奠定了基础。In accordance with the British Standard BS7448, Crack Tip Opening Displacement （CTOD） fracture toughness tests are conducted at different grades of UOE pipe steels. Combining with the standards CSA Z662-07 and NDV-OS-F101, this paper improved the fracture toughness evaluation in respects of the specimen types, notch positions and post-test metallography. The result shows that both X70 and X65 grades of LSAW （longitudinal submerged arc welded） pipeline steel have good toughness properties, and meet the requirement of the NDV-OS-F101 standard. X70 pipeline steel toughness of different parts distribute range from best to worst is： base metal, weld metal and HAZ （heat affected zone）. The HAZ toughness of X65 pipeline steel is better than its base metal and weld metal. Because the base metal of X65 pipe steel contains a number of inclusions and pores and has delamination cracks on its fractograph. Thus lead CTOD test results to be highly disperse. Besides, as it contains a large amount of brittle structure M-A islands and mischcrystal structures which usually distribute unevenly, the weld metal toughness of X65 pipe steel declines. The results provide a basis for the improvement of offshore pipeline steels manufacturing and lay the foundation for the security assessment of offshore structures.

关 键 词：管线钢 CTOD 断裂韧性 焊接接头 

分 类 号：TG142.1[一般工业技术—材料科学与工程]