Cr微合金化低碳钢热变形行为

采用Gleeble-3500热模拟机对一种含微量合金元素Cr、Mn、Ti的低碳钢在变形温度700～1050℃.应变速率0.01～0.1s~(-1)条件下的热变形行为进行研究.结果表明:单相奥氏体区和铁索体区,峰值应力随变形温度的降低而升高,在两相区,峰值应力随着变形温度的降低而降低;在775～850℃与950～1050℃的温度区间,峰值应力的大小基本相当.建立了热加工图,并通过组织观察对其热加工图进行了解释.根据流变应力曲线,确定了试验低碳钢铁素体区的热变形激活能和热变形方程.

Hot deformation behavior of Cr micro-alloyed low carbon steel

Hot deformation behavior of a low carbon steel with the addition of chromium, manganese and titanium was investigated by means of simulation on a Gleeble-3500 simula for at 700～1050℃ and strain rates of 0.01 ～0. 1s~(-1). The results show that the peak flow stress increases with reducing the deformation temperature in auslenite and ferrite regions, and decreases in γ-α region. The value of peak flow stress at 775～850℃ in ferrite region is similar to that at 950 ～ 1050℃ in austenite region. Processing map for hot working was established and discussed based on the mierostruture observation. The apparent activation energy for hot deformation and the hot deformation equation in ferrite for the steel are determined according to the flow stress curve.