22CrS齿轮钢变形奥氏体动态再结晶行为及组织演变

采用Gleeble1500热模拟试验机研究了一种新型Mn Cr系齿轮钢在变形量为70%,变形速率为0.1～1s-1,变形温度为850～1150℃,原始奥氏体晶粒尺寸为70～150μm条件下的动态再结晶行为及再结晶后奥氏体晶粒尺寸的变化规律·研究结果表明:在一定的变形量下,变形速率、变形温度、奥氏体晶粒尺寸是影响再结晶的3个因素,只有变形条件Z小于上临界值Zc时才会发生动态再结晶·再结晶后奥氏体晶粒尺寸 D是由变形条件Z惟一地决定而与原始奥氏体晶粒大小无关,Z增加, D减小,二者符合关系式Z=A D-3.91·

Dynamic Recrystallization of a 22CrS Gear Steel

The dynamic recrystallization and austenite grain size after recrystallization in a new Mn-Cr gear steel were studied at a strain up to 0.7, at a range of temperature from 850 to 1 150°C , at strain rate from 0.1 to 1 s^-1 and at initial austenite grain size from 70 to 150 μm using a Gleeble 1500 thermomechanical test system. The experimental results show that strain rate, deformation temperature and initial austenite grain size are three factors with strong effects on the dynamic recrystallization. Dynamic recrystallization takes place if deformation condition Z is less than the critical value of Zc. The mean dynamically recrystallized grain size (D) is determined only by deformation condition Z and does not depend on the initial austenite grain size. D decreases with increase of Z. The equation of Z=AD^-3.91 was derived to show the relationship between D and Z.