精冲钢半冲特征连接强度实验研究

Experimental investigation on connection strength of half-blanking feature for fine-blanking steel

半冲是精冲零件的重要特征之一。为研究半冲特征的连接强度特点,以厚度为3.8 mm的C20E碳素结构钢板材和厚度为4.5 mm的16MnCr5合金钢板材为实验材料,开展了工字型半冲特征成形和剪切失效实验,分析了半冲深度、成形工艺参数和特征形状对半冲特征连接强度的影响。研究结果发现:当半冲深度达到材料的半冲极限深度前,随着半冲深度的增加,半冲特征的连接强度逐步增加,最后趋于稳定;而当半冲深度达到材料的半冲极限深度时,半冲特征会提前发生开裂失效。此外,工艺参数中反顶力和凸凹模间隙对连接强度的影响较小,而半冲特征凸台的接触包络面积与有效剪切面积对连接强度的影响显著。

Half-blanking is one of the important features for fine-blanking parts.Therefore,in order to study the connection strength characteristic of the half-blanking feature,C20E carbon structural steel sheet with the thickness of 3.8 mm and 16MnCr5 alloy steel sheet with the thickness of 4.5 mm were used as experiment materials,the forming of I-shaped half-blanking feature and the shear failure experiments were carried out,and the influences of half-blanking depth,forming process parameters and feature shape on the connection strength of the halfblanking feature were analyzed.The research results show that before the half-blanking depth reaches the half-blanking limit depth of material,with the increasing of half-blanking depth,the connection strength of the half-blanking feature gradually increases,and finally tends to be stable.When the half-blanking depth reaches the half-blanking limit depth of material,the half-blanking feature cracks in advance.In addition,among the process parameters,the counter force and the clearance between punch and die have little influence on the connection strength,while the contact envelope area and the effective shear area of the half-blanking feature boss have a significant impact on the connection strength.