摘要
介绍了SA335P91钢管对接全位置固定单面焊双面成形接头焊缝交汇处所产生的背面裂纹。断口电镜扫描和能谱分析的结果表明 :此类裂纹属于结晶裂纹 ,产生的原因是由于该处形成了粗大且方向性极强的胞状树枝晶组织 ,出现了比较严重的结晶偏析并导致晶界上S、P含量偏高 ,此外 ,该处所存在的背面凹坑也会导致收缩时产生较大的应力集中。
The back cracks initiated from welding conjuction in the SA335 P91 steel tube butt joint by all-position fixed one side welding with double shaped were investigated in present paper. It is shown from the electronfractography and energy spectrum analysis that this is the one of crystal crack. and the reason for these cracks is, at first, attributed to coarse cellular fir-tree crystal with intensive directivity in which the compositions of sulfur and phosphorus increase along the grain boundary for the serious crystal aliquation. In addition, it is because of the higher stress concentration induced from the contraction in back rut.
出处
《压力容器》
2004年第5期36-40,共5页
Pressure Vessel Technology
