中厚壁毛管内皱褶缺陷成因分析及对策

锥形辊穿孔机在中厚壁毛管穿孔过程中,由于穿孔顶头辗轧段表面失效起皱,致使毛管内壁形成众多纵向平行且类似于裂纹的内皱褶缺陷。结合现场实践,在分析内皱褶缺陷产生原因的基础上,通过采用H13钢顶头、改进穿孔工艺参数、严格控制毛管减径率等措施,消除了穿孔毛管的内皱褶缺陷,为后续的冷加工变形提供了合格的原料管,有效地提高了产品的一次成材率。

Investigation of Cause for Inner Folds of Medium/Heavy-wall Pierced Shells and Countermeasures as Taken

During the course of piercing medium/heavy-wall shells with the cone type piercer(CTP),lots of longitudinally parallel crack-like folds are formed on the inner surface of the shell due to failure of the plug with folded surface of its rolling section.Taking the actual piercing operation situation and the cause for the inner fold as identified via the investigation into consideration,preventative actions are taken,including adopting the plug made in the H13 steel,improving the piercing process parameters,and strictly controlling the reduction ratio of the shell,etc.As a result,the said defective fold is eliminated,thus qualified blanks are ensured to be provided to the following cold-working process,and the primary yield greatly is considerably enhanced.