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在DSS-25试验机上,用拉伸板状试件的方法,进行了中、低速(10~(-5)～10~(-1)s~(-1))的试验.该试验机在全部拉伸过程中可保持其加载速度恒定.为了获得更高的应变速度,组装了氮气膨胀式拉伸仪,它的速度可达10~(-1)～10~2s~(-1),并且可以给出应力-时间和应变-时间关系曲线.含铜软钢的试验表明,应变速度对变形抗力有明显的影响.在试验条件下,随着加载速度的增加,变形抗力有显著的提高.根据金属位错的理论,确定了变形抗力的理论结构模型,它包括应变速度ε,变形程度ε对变形抗力的影响和A、B、n_1、n_2等系数.?从试验结果来看,在很宽的变形速度的范围内,该公式较好的反映了实际情况.
Medium and low speed (10 ~ (-5) ~ 10 ~ (-1) s ~ (-1)) tests were carried out on the DSS-25 testing machine by means of tensile plate test, In order to obtain a higher strain rate, a nitrogen expansion extensometer was assembled with a speed of 10-1 to 10-2s -1, And the stress-time and strain-time curves can be given.The experiments on copper-containing mild steel show that the strain rate has a significant effect on the deformation resistance.With the increase of the loading speed, the deformation resistance increases significantly under the test conditions According to the theory of metal dislocation, the theoretical structure model of deformation resistance is determined, which includes the influence of strain rate ε, deformation degree ε on deformation resistance and A, B, n_1, n_2 etc. From the experimental results, Within a wide range of deformation speed, the formula better reflects the actual situation.