变形温度与冷却速率对含Nb中碳钢晶粒细化的影响

来源期刊：钢铁2009年第4期

论文作者：赵英利 时捷 董瀚 谢刚

文章页码：77 - 81

关键词：晶粒细化； 再结晶； 直接淬火； 逆相变

Key words：grain refinement； recrystallization； direct quenching； reverse transformation

摘    要：利用Gleeble-1500热模拟试验机,以含Nb中碳钢为研究对象,研究了不同变形温度与冷却速率对再加热淬火后奥氏体晶粒细化的影响及其晶粒细化的机制。结果表明:经热变形后直接淬火+再加热淬火工艺得到的奥氏体晶粒尺寸均小于10μm,且随热变形温度的降低,原奥氏体晶粒由等轴晶粒变成扁平化晶粒,经再加热淬火后,得到的奥氏体晶粒逐渐细化;与变形后以5℃/s冷速缓冷的工艺相比,变形后直接淬火经再加热淬火后的奥氏体晶粒细化更明显。

Abstract: By using Gleeble-1500 machine,the effect of different deformation temperature and cooling rate on grain refinement of austenite grains after reheat quenching and the mechanism of grain refinement were studied.The results show that austenite grains size are all less than 10 μm by hot deform followed by direct quenching,and then reheat quenching,austenite grains refining with decreasing deformation temperature as a result of prior austenite grains become from equiaxed grains to pancake grains;The finer austenite grain can be obtained by hot deform followed by direct quenching and then reheat quenching,compared with hot deform followed by slow cooling at 5 ℃/s and then reheat quenching.