关键词: 绝热温升, 应变速率, 超高强钢, 应变诱导马氏体相变, 分离式霍普金森拉杆, 应变增量试验, 应变受控试验

Abstract: To investigate the coupled effect mechanism of adiabatic temperature rise and strain rate on strain-induced martensitic phase transformation in FA ultra-high-strength steel under high strain rates, this study improved the traditional split Hopkinson tensile bar (SHTB) apparatus by adding an energy absorption bar and a momentum capture sleeve, thereby addressing the issue of multipulse loading interference in conventional SHTB tests and successfully developing single-pulse loading technology. On the basis of this experimental technique improvement, an innovative decoupled experimental scheme was proposed: the adiabatic temperature rise effect was effectively separated through strain increment tests (quasi-isothermal loading), and the influence of the strain rate was quantitatively analyzed. Furthermore, by combining strain-controlled tests (non-isothermal loading), the influence of an increase in the adiabatic temperature was quantitatively analyzed. A comparison of the inhibitory effects of an increase in the adiabatic temperature and strain rate on the strain-induced martensitic phase transformation content revealed that the inhibitory effect of an increase in the adiabatic temperature on the strain-induced martensitic phase transformation content dominates, whereas an increase in the strain rate only marginally enhances its inhibitory effect.

Key words: adiabatic heating, strain rate, ultra-high-strength steel, strain-induced martensitic phase transformation, split Hopkinson tensile bar, increment test, strain-controlled test