【摘要】 对成分为0.18C-0.22Si-0.60Mn(质量分数)的低碳钢在1 100~750℃之间的奥氏体动态再结晶及动态相变行为进行了研究。确定了此钢奥氏体发生动态再结晶的临界应变条件及完全动态再结晶后的晶粒尺寸。计算表明,在奥氏体低温区大变形以致使奥氏体发生完全动态再结晶时,可得到6~9μm的奥氏体晶粒尺寸。在Ae3以下,变形可以引发动态相变。但奥氏体快速冷却明显推迟了动态相变的发生。与相同温度下单一奥氏体变形相比,有动态相变发生时应力值不增加或降低,其降低程度随变形温度的下降而增加。更多还原

【Abstract】 The behavior of austenite dynamic recrystallization and dynamic transformation within the temperature range of 1 100~750 ℃ was studied for a low carbon steel with a composition of 0.18C-0.22Si-0.60Mn.The critical strain for austenite dynamic recrystallization and the austenite grain size after completely dynamic recrystallization were determined.The calculations show that,under the condition of heavy reduction at low temperature,the completely dynamic recrystallization of the austenite occurs and the austenite grains with a size of 6-9 μm can be obtained.When deformation temperature is lower than A(e3),the dynamic transformation may occur.However,the rapid cooling of austenite postpones dynamic transformation remarkably.When austenite dynamic transformation occurs,the stress value decreases compared with sole austenite deformation at the same temperature.The decrement increases with deformation temperature decreasing.更多还原