汽车用高强车轮钢LQ540的研制

Development of High Strength Automobile Wheel Steel LQ540

以汽车用高强车轮钢LQ540为研究对象,选择Gleeble-3800热模拟试验机测定了LQ540动态CCT曲线,采用金相组织观察、TEM及力学性能测试等手段分析了实验室条件下所试制的试验钢组织和性能。根据优化的试验结果,进行了高强车轮钢LQ540的工业试制。结果表明,试制样品的显微组织为铁素体加珠光体及少量的贝氏体,屈服强度大于450 MPa,抗拉强度大于540 MPa,延伸率在23%以上。产品应用于实际车轮冲压效果良好,疲劳性能达到62万次以上。

Taking the high strength automobile wheel steel LQ540 as the study subject,the dynamic CCT curve of LQ540 is measured by Gleeble-3800 thermal simulator,the microstructures and properties of the experimental steel obtained by trial manufacturing under lab conditions are also analyzed by observing metallographic microstructure,examined by TEM and by means of testing mechanical properties.Based on the optimized experiment results,the high strength wheel steel LQ540 is produced by the way of industry trial-production.The results show that the microstructures of the sample are mainly consisted of ferrite,pearlite and a few bainite,and its yield strength and tensile strength are over 450 MPa and 540 MPa respectively,its elongation is over 23%.LQ540 steel demonstrates good properties after being stamped and used to make a wheel with more than 620,000 fatigue cycle times.