对比了SY/T4109-2013与SY/T4109-2005标准中射线检测缺陷质量分级的区别,分析了圆形缺陷、条形缺陷、未焊透、未熔合、内凹、烧穿与内咬边等焊接缺陷质量分级的合理性.结合石油天然气管道焊接实际,指出SY/T 4109-2013标准对单个圆形缺陷的评级过于严格,并举例提出增加气孔、烧穿影像与母材进行黑度比较的可行性,对内咬边缺陷评定提出了建议.

This paper compares the X-ray defect quality classifications according to SY/T4109-2013 and SY/T4109-2005 two standards,respectively, and analyzes the rationality of quality grading for the welding defects such as circular defects,strip defect,incomplete fusion,concave,burn through and internal undercut.Combined with the oil and gas pipeline welding practice,some different views on these standards were presented.The author points out that the rating by SY/T4109-2013 standard on the single circular defect is too harsh,and shows the feasibility, with examples, of making comparison of the densograph of porosity and burn through with the parent material.This paper puts forward a proposal for internal undercut defect assessment.