钢的强导比与绝热剪切敏感性关系的研究

提出用钢的强度与热导率的比值(强导比)来表征钢的绝热剪切敏感性。通过对若干钢约束爆炸圆管试验结果的分析表明:随强导比的降低,钢在一定爆轰条件下的绝热剪切敏感性增加,表现为剪切带密度下降,同时相变带过渡到形变带;对应一定的爆轰条件,强导比有两个临界值,如果强导比值低于较小的临界值,材料将不以绝热剪切方式(集中的剪切变形)破坏;较大的临界值决定材料绝热剪切变形的方式,当材料的强导比低于它时材料以形成形变带的形式失效,反之则以"白亮带"形式破坏。

Study of relationship between the ratio of strength to thermal conductivity and adiabatic shearing sensitivity of steels

A ratio of strength to thermal conductivity is proposed to characterize the adiabatic shearing sensitivity for steels. It is shown by constraint exploding cylinder technology that, with value of the ratio decreasing, the adiabatic shearing sensitivity of steels decreases, which characterized by the decreasing density of adiabatic shear bands (ASBs) and transition of ASBs from the transformed to deformed ones; there are two critical values for the ratio under a specific exploding condition, no localized adiabatic shearing will occur if ratio value is lower than the small critical one; the large critical value determines the way of adiabatic shearing: transformed ASBs will form if the ratio value is higher than the critical one, otherwise deformed ASBs will form.