高钢级管线钢摩擦焊焊接接头组织与硬度分析

Analysis on Microstructure and Hardness of High Steel Grade Pipeline Steel Friction Welding Joint

为了提高高钢级管线钢焊缝的冲击韧性,采用连续驱动摩擦焊对X80管线钢进行了焊接,并对其焊接接头的组织及硬度进行了分析和检测。结果表明,X80管线钢连续驱动摩擦焊焊接接头焊缝区组织为铁素体和粒状贝氏体,热影响区的组织由原始的针状铁素体转变为先共析铁素体、针状铁素体及粒状贝氏体。焊接接头的硬度高于母材,其中焊缝区域硬度最高,达到了247.4HV10,其次是热影响区,母材的硬度最低,且在焊缝两侧,硬度值呈对称分布。

In order to increase the weld impact toughness of high grade pipeline steel, it adopted continuous drive friction welding to weld X80 pipeline steel, and carried out analysis and detection for the mierostructure and hardness. The resuhs showed that the microstructure of weld zone of X80 pipeline steel welding joint is acicular ferrite（AF） and granular bainite. The microstructure of heat affected zone is proeutectoid ferrite（PF）, acicular ferrite and granular bainite transtbrmed by original aeicular ferrite. The hardness of welding joint is higher than that of parent metal, which the weld zone hardness is the highest, reaches 2d-7.4HV10, followed by the heat affected zone, and the hardness parent metal is the lowest. Besides, on the hoth sides of weld zone, the hardness distribution is symmetrical.