X100螺旋埋弧焊管焊接接头冲击韧性研究

Research on Impact Toughness of X100 SAWH Pipe Welded Joint

采用落锤冲击试验法测试了X100螺旋埋弧焊管焊接接头的低温冲击韧性,并进行了断口特征及微观组织分析。结果表明,沿管壁厚度方向的冲击韧性变化不明显;焊接接头的冲击韧性呈现母材冲击韧性最高,约是焊缝和热影响区的1倍,焊缝略高于热影响区;母材韧窝尺寸大且深,焊缝韧窝尺寸均匀但较浅,焊接热影响区以小尺寸韧窝为主,含少量大尺寸韧窝;焊缝和粗晶区的大尺寸条状或棒状M-A岛使冲击韧性下降。

In this paper,the impact toughness of X100 SAWH pipe welded joint was tested by using drop weight tear test（DWT＇F） method at low temperature,and the fracture feature and microstructure were analyzed. The results showed that the impact toughness along wall thickness does not change obviously. The impact toughness changes greatly from weld,heat affected zone to base metal ,and the impact toughness of base metal is the highest about one time compared to those of the weld and heat affected zone ,and the impact toughness of weld is slightly higher than that of heat affected zone. The fracture feature displays large and deep size dimple in base metal,uniform and shallow size dimples in weld,and mainly to the small size dimple with a small amount of the large size dimple in heat affected zone. The large size bar or round M-A island make impact toughness decrease.