摘要
采用Gleeble-3500热模拟试验机模拟了屈服强度500 MPa级高建钢热变形奥氏体的动态连续冷却转变过程,结合金相法绘制试验钢的CCT曲线,并对相变组织进行维氏硬度测试.试验结果表明,当冷速低于2.5℃/s时,形成多边形铁素体、针状铁素体和珠光体的混合组织;在5～30 ℃/s的冷速范围内,形成针状铁素体和粒状贝氏体的混合组织;在冷速50℃/s时,开始出现少量板条贝氏体组织.随着冷速的增大,组织细化,连续冷却转变组织硬度增加.试验钢两阶段变形后的控冷工艺窗口为5～25℃/s.
The continuous cooling transformation of deformed austenite of steel for high-rise building with yield strength more than 500 MPa was investigated by Gleeble-3500 thermal simulator,the microstructures were observed to help drawing the CCT curve and the hardness was tested.The experimental results showed that the transformed microstructures were polygonal ferrite,acicular ferrite and pearlite when the cooling rate was slower than 2.5 ℃/s.With the cooling rate ranging from 5 to 30 ℃/s,acicular ferrite and granular bainite became dominated.When the cooling rate further increased to 50 ℃/s,a small amount of lath bainite appeared.As the cooling rate increased,the microstructures were finer,and the hardness increased.The optimal range of cooling rate was from 5 to 25 ℃/s.
出处
《上海金属》
CAS
北大核心
2014年第5期6-8,18,共4页
Shanghai Metals
基金
江苏省科技成果转化项目(项目编号:BA2012040)
