通过在不同塑性应变水平下的加载-卸载实验,对TRIP600和H220BD两种高强度钢板卸载后的应变回复行为及其随塑性应变的变化规律进行了详细的分析,并建立了弹性模量计算模型。结果表明:高强度钢板卸载后产生的应变回复由弹性部分和非弹性部分组成,其中非弹性应变回复所占比例在塑性应变为0.2时可达20%;弹性模量随着应变的增大而下降,且下降幅度逐渐减小,当应变增大到一定水平时弹性模量趋于一个稳定值。
By the tensile testing under different plastic strains, the composition of the inelastic strain recovery of TRIP600 and H220BD steel during unloading and its variation regulation with the plastic strain was analyzed in detail here. Then an elastic modulus model was proposed. It is shown that the total strain recovery is composed by the elastic strain recovery and the inelastic strain recovery. Among which, the percentage of the inelastic strain recovery can reach 20% when the plastic strain is 0.2. Elastic modulus decreases with the increase of the plastic strain. However, the decrease slope descends gradually and the elastic modulus tends to be constant when the plastic strain reaches to some level.