不同合金设计的X70螺旋埋弧焊管性能分析

摘要

对比分析了不同合金设计的X70螺旋埋弧焊管的化学成分、拉伸试验、冲击试验及DWTT等试验结果,对比发现Mo对管线钢的强度有比较大的影响,但对于韧性影响不显著.不添加Mo的X70钢管,经过对轧制工艺的优化,各项性能指标能达到标准要求.从金相组织来看,管体组织以块状铁素体与多边形铁素体为主,不同于添加Mo的X70钢管,后者以粒状贝氏体为主,但不添加Mo的X70钢管也具有较小的包辛格效应值.%This article compared and analyzed some test results of X70 SAWH pipe with different alloy content design, such as chemical composition, tensile test, impact test, DWTT and etc. The results indicated that the effect of Mo on pipeline steel strength is great, while the effect of Mo on toughness is not great. The properties of X70 pipe without Mo can meet the requirements of the standard after optimizing rolling process. The structure of pipe body mainly consist of granular ferrite and polygon ferrite, which is different from X70 steel without Mo, the structure of X70 steel without Mo mainly consist of granular bainite, and the Bauschinger effect value of X70 pipe is lower.