HFW焊管焊缝点状缺陷产生原因及预防措施

某HFW焊管在机组生产过程中，超声波检测出钢管焊缝存在不规则分布的点状缺陷，通过对点状缺陷位置的焊缝形貌和金相组织观察，以及生产过程的工艺控制情况分析了点状缺陷产生的原因。结果显示，原材料钢板边缘的质量及其在成型过程中的状态是产生点状缺陷的主要原因；其次，生产过程中成型和焊接工艺参数匹配不合理也会造成不同程度的点状缺陷出现。为避免生产时产生点状缺陷，增加了对原材料和板边质量的预防性控制措施，优化了成型和焊接工艺参数，并结合焊接时毛刺的颜色和形状，以及在线超声波检测的波形特点，实时调整成型和焊接工艺参数的匹配。生产实践表明，通过采取上述控制措施，可以显著降低点状缺陷产生的概率，取得了良好效果。

The Causal Analysis and Preventive Measures of HFW Pipe Weld Spot Defect

In the production process of HFW welded pipe, some spot defects were distributed non?niformly among the weld seam by ultrasonic testing. Through the observation of the weld morphology and metallographic structure of the spot defect, as well as the process control in the production process, the causes of the spot defect were analyzed. The results indicated that the steel plate edges quality and the situation when its in the process of the pipe forming were the most important causes to the spot defect, in addition, the spot defect also resulted by the improper parameters set of the forming and welding process. To avoid the possibility to produce the spot defects when running the mill line, take the preventive actions to the quality of the base material and the edges of the steel plate, optimize the forming and welding process parameters set, and based on the color and figure of weld bead and the ultrasonic testing to adjust the process parameters matching. The practice of production indicated that the probability of the spot defects occurrence was reduced remarkably by the actions above, the quality of the product was improved, and it obtained a good result.