管线钢板亚表面隐蔽式裂纹缺陷成因分析

Analysis on Cause of Concealed Cracks on Subsurface of Pipeline Steel Plate

采用喷砂、着色探伤、冷弯、阶梯式刨削及高、低倍金相检验分析方法,研究了两种规格管线钢板受力后表面所产生的板条状翘皮裂纹缺陷(卷板)和开口呈撕裂状纵向裂纹缺陷(平板)的形成原因。结果表明,两种规格钢板受力后不同的表面缺陷同属于一种缺陷的不同表现形式,受力后表面缺陷形成的主要原因是铸坯皮下气孔遗传所致。

Lath-shaped seamed cracking defects（coiled steel plates） and tearing longitudinal cracking defects（flat steel plates） on surface of two different steel plates after forced are investigated by blasting,penetrant-dye method,cold-bending,stepped chipping and macrographic and micrographic examinations.The results show that the surface defects above-mentioned belong to the same type of defects with different indicating appearances which are caused by the skin pinholes inherited from casting billets.