某型翻转吊具索节裂纹原因分析及工艺改进

Cause analysis and process improvement of cracks in the cable joint of a certain turnover spreader

针对某型翻转吊具索节新品使用前磁粉探伤检查中出现多处裂纹的问题,文中建立了以索具裂纹为顶事件的故障树,从设计、加工、装配、使用等4个方面,逐级梳理造成该顶事件的9个底事件。通过对索具裂纹故障树分析和取样机理分析得出,锻造产生的应力、终锻温度偏低、锻造毛坯尺寸小、加工余量小、探伤时机不恰当,加之抛丸工序和镀锌层的干扰,影响了磁粉探伤的检测结果,导致出厂合格的吊具在使用方复检时出现裂纹问题。根据索具裂纹产生的原因,通过加强原材料复验、优化锻造工艺、改善加工工艺等措施解决了索具裂纹问题,对此类吊索具产生裂纹的原因分析方法与实际问题的解决具有指导意义。

For the case that many cracks were found in the magnetic particle flaw detection inspection of a new type of turnover spreader rope joint before use,the author established a fault tree with spreader crack as the top event,and sorted out the nine bottom events that caused the top event step by step from the aspects of design,processing,assembly and use.Through the fault tree analysis and sampling mechanism analysis of spreader cracks,it is concluded that the stress caused by forging,low final forging temperature,small forging blank size,small machining allowance,inappropriate flaw detection opportunity,and the interference of shot blasting process and galvanized layer have affected the detection results of magnetic particle flaw detection,which led to the cracks found in the qualified spreader when re-examined by the user.According to the causes of cracks in spreader,the author solved the crack problem by strengthening the reinspection of raw materials,optimizing forging technology and improving processing technology,which has guiding significance for the analysis of the causes of cracks in this kind of spreader and the solution of practical problems.