基于Dynaform模拟冲压工艺对17%Cr超纯铁素体不锈钢表面起皱的影响

采用Dynaform模拟和实验验证相结合的方法研究了冲压工艺(等效应变、减薄率等)对17%Cr超纯铁素体不锈钢起皱的影响。结果表明:17%Cr超纯铁素体不锈钢冲压起皱并不是一开始就产生,而是拉深到一定程度才产生的。在恒速模式(10~40mm/min)和加速模式下冲压工艺对17%Cr超纯铁素体不锈钢起皱改善作用不大。经Dynaform有限元分析得知,增大压边力会使减薄率显著增大,而对等效应变影响不大;各截面处减薄率和等效应变略有差别,其中减薄率在45°方向最大,0°方向次之,90°方向最小,等效应变的规律则相反。此外,当首次拉深深度在临界起皱拉深深度以下时,采用中间退火工艺可以明显改善拉深件内侧起皱,但对外侧起皱的改善作用有限。

Influence of Stamping Process by Dynaform Simulation on the Surface Ridging of 17%Cr Ultra-pure Ferritic Stainless Steel

The influence of equivalent strain and reduction ratio of stamping process on surface ridging of 17%Cr ultra-pure ferrite stainless steel were studied by combination of Dynaform software and experiment vertification.The results showed that stamping ridging of 17% Cr ultra-pure ferrite stainless steel was not generated at the initial stage, it was generated until a certain degree of deep drawing.The improvement ridging effect of 17%Cr ultra-pure ferrite stainless steel was not obvious, under the model of constant speed and acceleration speed for stamping process from 10-40 mm/min.Based on Dynaform finite element analysis, the improvement blank-holder force could enhance reduction ratio of deep drawing, which has no obvious effect on the equivalent strain.The reduction ratio and equivalent strain on cross section area was slightly different, and the value of reduction ratio was ranked in decreasing order: 45°<0°<90°, while the rule is opposite for equivalent strain.In addition, the intermediate annealing process can obviously improve the inside ridging of deep drawing parts when first drawing depth below the critical ridging in deep drawing depth, while the effect was limited for outside ridging.