一、问题的提出在焊接缺陷中裂纹是具有发展性的危险缺陷、冶金部钢铁研究院对28台球罐取样分析的结果再一次证明这个论断,他们的结论是,气孔、夹渣、未焊透等原生缺陷虽然超标(即超制造标准),但没有发现在使用中扩展;而焊接裂纹却有的在使用中扩展。特别是这些扩展常常含有沿壁厚方向的。正因为这个原因,各国制造标准均将裂纹列入“不允许存在的”缺陷。有的资料统计,在强度钢的焊接裂纹中,热裂纹占10%,冷裂纹占90%,近年来的开罐检查资料,都提到冷裂纹均为延迟裂纹。作为一个无损检测人员了解焊接延迟裂纹的产生要素、特征,以便采取相应的检测对策,当然是十分重要的。 First, the problem raised Cracks in the welding defects is a development of dangerous defects, the Ministry of Metallurgical Iron and Steel Research Institute 28 ball tank sample analysis results once again prove this assertion, they concluded that the pores, slag, not penetration Although the primary defects such as excessive (that is, over-manufacturing standards), but did not find in the use of expansion; and some welding cracks in use to expand. In particular, these extensions often contain along the wall thickness direction. It is precisely for this reason that national manufacturing standards include cracks as “impermissible” defects. Some statistics show that, in the strength of steel welding cracks, 10% of the hot cracks, cold cracks accounted for 90% of the open canning inspection data in recent years, are referred to as cold cracks are delayed cracks. As a non-destructive testing personnel to understand the production of welding delay cracks elements, characteristics, in order to take appropriate measures to detect, of course, is very important.