冷轧双相钢纯弯曲性能试验研究

Experimental investigation on pure bending testing for dual phase steels

研究了2个级别双相钢HC590DP和HC780DP在小应变下的单轴拉伸性能和纯弯曲性能。结果表明:在产生塑性应变初始阶段,相同应变下HC780DP应力反而小于HC590DP,但通过某临界点后,HC780DP应力超过HC590DP。2种材料在0.02%的小应变时,弯曲强度均大于拉伸强度;且材料在弯曲过程中的应变强化硬化能力要高于单轴拉伸;相比冲压成形,HC590DP和HC780DP在弯曲变形加工过程中(如辊压、折弯成形)的材料变形抗力大,塑性加工硬化率高,回弹量大。

Both the tensile test and pure bending test were accomplished to investigate the formability for two dual phase steels HC590 DP and HC780 DP with small plastic strain. The results showed that the stress of HC780 DP was smaller than that of HC590 DP in the beginning period and then grew larger after reaching a balance point. With a plastic strain of 0. 02 %,the bending strength was larger than the tensile strength for both steels. During the entire forming,the hardening rate was also relative higher in bending than in tensing. Both of the dual phase steels had a higher resistance,hardening rate and springback in bending process compared to stamping process.