某产品823钢壳体内膛疵病原因分析

Cause Analysis of Defects in the Inner Bore of the Shell of an 823 Steel Product

目的研究某产品关键零件用壳体823钢在冲拔过程中,毛坯内膛出现侧壁拉裂和底部缩孔疵病的原因。方法通过理论分析毛坯在冲拔过程中的变形机理和金属流动规律,结合理化检测和工艺试验等手段,对该疵病产生的原因进行了系统分析与验证。结果准确找到了该疵病产生的原因。结论 823钢原材料存在缩孔残余及二次缩孔,是造成弹体毛坯底部缩孔疵病和侧壁拉裂疵病的根本原因;通过靶场射击动态考核试验和增加超声波探伤检验工序的产品,即使存在缩孔残余及二次缩孔,也不影响产品使用性能。

Objective The aim of the study is to investigate the causes of the wall cracking and shrinkage cavity defects at the bottom of the inner bore of the shell of a semi-finished 823 steel product in the drawing process. Methods Through the theoretical analysis of the semi-finished product on the deformation mechanism and the law of metal flow in the process of drawing, combining with the physical and chemical testing and process test, the author systematically analyzed and validated the causes of the fault. Results As a result, the cause of the fault was found with high accuracy. Conclusion Residual and secondary shrinkage cavity were found in the 823 steel raw materials, which were the essential causes of the defects in the shrinkage cavity at the bottom of the projectile and wall cracking faults. For the products that passed the range shooting dynamic tests and the ultrasonic flaw detection process, the presence of the residue and secondary shrinkage did not affect the performance of the shell.