18CrNiMo7-6风电齿轮钢的动态CCT曲线
Dynamic CCT curve of 18CrNiMo7-6 wind power gear steel
路峰 1李琦 2孙雪娇 1邱国兴2
作者信息
- 1. 山东钢铁股份有限公司技术中心,山东济南 271104
- 2. 西安建筑科技大学冶金工程学院,陕西西安 710055
- 折叠
摘要
利用Gleeble-3800热模拟机对18CrNiMo7-6风电齿轮钢进行1150和1050 ℃下变形30％的双道次压缩试验.测定了 0.1～30 ℃/s冷却速率下18CrNiMo7-6风电钢的热膨胀曲线,结合金相-硬度法绘制了 18CrNiMo7-6风电齿轮钢的动态连续冷却转变曲线,分析了不同冷却速率下18CrNiMo7-6风电齿轮钢的组织转变情况,探究了冷却速率对其组织演变和硬度的影响规律.结果表明,18CrNiMo7-6风电齿轮钢的相变温度为Ac1=759 ℃,Ac3=835 ℃.在高温状态双道次轧制的试验条件下,当冷速小于0.5 ℃/s时,试验钢组织为铁素体+珠光体及少量贝氏体;当冷却速度为0.5～1 ℃/s时,铁素体逐渐消失,钢中开始出现板条贝氏体;随着冷却速度的继续增大,钢中贝氏体组织含量先增加后减少;当冷却速度大于10 ℃/s时,试验钢组织为全马氏体;随着冷速的增加,试验钢的硬度由295 HV逐渐升高至449 HV.
Abstract
Double-pass compression tests of 18CrNiMo7-6 wind power gear steel with 30％deformation at 1150 and 1050 ℃ were carried out by Gleeble-3800 thermal simulator.The thermal expansion curves of the steel at cooling rates of 0.1-30 ℃/s were measured,and the dynamic continuous cooling transformation curves of the steel were drawn by metallographic-hardness method.The microstructure transformation of the steel at different cooling rates was analyzed,and the influence of cooling rate on its microstructure evolution and hardness was explored.The results show that the phase transition temperature of the 18CrNiMo7-6 wind power gear steel is Ac1=759 ℃,Ac3=835 ℃.Under the experimental conditions of double-pass rolling at high temperature,when the cooling rate is less than 0.5 ℃/s,the microstructure of the tested steel is ferrite+pearlite and a small amount of bainite.When the cooling rate is 0.5-1 ℃/s,ferrite gradually disappears and lath bainite begins to appear in the steel.As the cooling rate continues to increase,the content of bainite in the steel increases first and then decreases.When the cooling rate is greater than 10 ℃/s,the microstructure of the tested steel is full martensite.With the increase of cooling rate,the hardness of the tested steel gradually increases from 295 HV to 449 HV.
关键词
18CrNiMo7-6风电钢/动态连续冷却转变曲线/组织/硬度Key words
18CrNiMo7-6 wind power steel/dynamic continuous cooling transformation curve/microstructure/hardness引用本文复制引用
出版年
2024
NETL
NSTL
万方数据