弧坑

压力钢管弧坑缺陷有限元分析

Finite element analysis for penstock 's crater defect

含弧坑缺陷压力钢管的安全评定

Safety assessment for penstock 's crater defects

文中报道了TIG焊接铁镍基合金鱼骨裂纹试样的焊缝弧坑裂纹及其二次裂纹断口扫描电镜观察的结果。

Solidification structure of the welding arc crater , fracture of crater cracks and their secondary cracks and fracture appearance of the solidification cracks in the crater studied by the scanning electron microscope are reported in this paper .

钨极氩弧焊（TIG）修整虽能改善焊缝形状，但弧坑处易于产生裂纹，疲劳寿命降低；利用最小二乘法给出立焊时疲劳寿命的估算式及S&N曲线。

Where as TIG dressing can result in crater cracks and therefore shorten the fatigue lifetime . The S & N curve and life estimation equation under vertical weld after TIG dressing are presented by least square method .

焊缝弧坑二维等轴树枝状晶的研究

Study on two & dimensional equiaxed dendrites in the welding arc crater

焊缝弧坑树枝状晶与凝固裂纹

Columnar crystals and solidification cracks in the welding arc crater

采用了简化评定和凹坑评定两种方法对管壁上的弧坑缺陷分别进行了评定，并给出了失效评定图。

Both simplified assessment and pits assessment were used , and fig of collapse assessment was showed .

采用电流衰减收弧控制方案，改善了弧坑的焊缝成形。

The manner of arc starting control increases succeed rate , current attenuation arc stopping control improves welding shaped of arc pit .

在收弧阶段采用适当焊接电流，增大送丝速度，减小离子气流量和焊接速度，以增加焊接热输入，可以实现收弧弧坑的填充。

The arc crater could be successfully filled by increasing wire feed speed , reducing ion gas flow rate as well as welding speed .

结合理论计算提出了焊缝弧坑产生凝固裂纹的晶间空隙与连接的三因素假说。

Finally , a hypothesis on " three factors " of formation of solidification cracks in the intercolumnar space and joint in the arc crater region was presented .