大直径、大壁厚K65钢级耐低温直缝埋弧焊管的开发

摘要

通过对K65钢板和钢管的试制，进行了低温夏比冲击试验和落锤撕裂（DWTT）试验，测得K65直缝埋弧焊管的低温韧性。结果显示，本次试制的K65钢管具有较好的低温韧性，同时计算得出钢管母材横向剪切面积为50%时低温韧脆转变温度（FATT）为-37℃，并且从母材成分、轧制工艺、组织和焊接工艺等方面分析了试制K65直缝埋弧焊管获得较好低温韧性的原因。%Through trial-production for K65 grade steel plate and steel pipe, the Charpy impact energy test at low temperature and drop weight tear test (DWTT) test were conducted, the low temperature toughness value of K65 SAWL pipe was obtained. The results indicated that the trial-produce K65 steel pipe is with good low temperature toughness, it also calculated the fracture appearance transition temperature (FATT) is -37℃ when the transverse shear area of base metal is 50%. The reason of low temperature toughness of K65 SAWL pipe was analyzed from several aspects, including base metal composition, rolling process, microstructure, welding process etc.