在锅炉四管的焊接施工中，小径管对接焊口为数甚多。对每个焊缝必须进行X射线透照检查。这类工件不仅曲率大，散射线影响严重，且管子厚度变化大，远远超出了一般射线照相技术所允许的范围。为了适应这种情况，提高缺陷的检出率，必须在保证探伤底片灵敏度和黑度的前提下，合理地选择探伤参数，采用合适的工艺，找到合理的规范要求。 In the boiler four pipe welding construction, a small number of pipe butt welding port number. X-ray examination of each weld must be performed. Such workpieces not only have large curvatures, have a strong influence on scattered rays, and vary widely in tube thickness, far beyond the range allowed by general radiography. In order to adapt to this situation and improve the detection rate of defects, under the premise of guaranteeing the sensitivity and darkness of flaw detection, reasonable selection of testing parameters and proper process should be used to find reasonable specifications.