中碳V-N微合金钢热变形行为

用Gleeble-1500热模拟试验机对中碳V-N微合金钢在不同变形温度(900~1050℃)及不同变形速率(0.005~30 s-1)的奥氏体区热变形行为进行研究。通过建立真应力-真应变曲线、动态再结晶图、功率耗散效率因子(η)图和应变速率敏感因子(m)图综合分析其热变形行为。结果表明,试验钢在1050℃、1 s-1变形条件下发生了动态再结晶,其真应力-真应变曲线、动态再结晶图、m图等方法得出的结果相互吻合。其中η图与m图差异很小,但由于应变速率敏感因子具有合理的物理意义,因此建议利用m图分析材料的热变形行为和选取最佳热变形工艺参数。

Hot deformation behavior of medium carbon V-N micro-alloyed steel

The hot deformation behavior of medium carbon V-N micro-alloyed steel was investigated by using Gleeble-1500 thermal simulator at 900-1050 ℃ and strain rates of 0.005-30 s~(-1).The behavior of test steel in hot deformation was analyzed through true strain-true stress curves,diagrams of dynamic recrystallization,power dissipation efficiency(η)map and strain rate sensitivity(m)map.The results show that dynamic recrystallization of the test steel occurs at 1050 ℃ and 1 s~(-1).The results through true strain-true stress curves,diagrams of dynamic recrystallization and m map are in accordance with each other.It shows slightly different between m map and η map,so m map is suggested to analyze the hot deformation behavior and choose the optimum hot deformation parameters,as m has the sound physical interpretation than η.