X52高频焊管焊缝冲击失效原因分析

Cause Analysis of X52 HFW Pipe Seam's Impact Toughness Failure

在-20℃的低温条件下对系列X52高频焊(HFW)管焊缝试样进行了夏比冲击试验,发现个别样品的冲击功明显低于正常平均值。采用扫描电子显微镜(SEM)、能谱分析仪(EDS)以及电子背散射衍射(EBSD)等显微分析技术研究其异常的原因。结果表明,冲击韧性异常试样的断口为解理或沿晶断裂形貌,在断口裂纹起源处存在夹杂物的偏聚区,焊管基体组织中存在严重的珠光体偏聚区,从而导致焊接过程中在焊缝区域形成珠光体条带组织。而冲击功正常的试样断口为韧窝形貌,基体组织分布均匀。X52焊管焊缝冲击韧性的异常降低主要与母材基体组织分布不均匀和焊接工艺有关。

Charpy impact tests of the series of X52 pipe welding seam specimens fabricated by high frequency electric welding(HFW)were carried out at low temperature of-20℃.It was found that the impact toughness values of some specimens were obviously lower than the normal level.The cause of the impact toughness failure of these abnormal specimens was analyzed by the scanning electron microscope(SEM),energy dispersive X-ray spectroscopy(EDS) and electron backscattered diffraction(EBSD).Experimental results show that i...