工程机械用Q890D钢中厚调质板的组织与性能均匀性  

Uniformity of microstructure and properties of quenched and tempered Q890D steel medium-thickness plate for construction machinery

作　　者：钟正根[1] 张瑞 袁清[2] 李忠波 薛艳生 刘红亮 Zhong Zhenggen;Zhang Rui;Yuan Qing;Li Zhongbo;Xue Yansheng;Liu Hongliang(Zhejiang Industry&Trade Vocational College,Wenzhou Zhejiang 325000,China;State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan Hubei 430081,China;Nanyang Hanye Special Steel Co.,Ltd.,Nanyang Henan 474571,China;Natural Steel Group Co.,Ltd.,Wenzhou Zhejiang 325000,China)

机构地区：[1]浙江工贸职业技术学院,浙江温州325000 [2]武汉科技大学、省部共建耐火材料与冶金国家重点实验室,湖北武汉430081 [3]南阳汉冶特钢有限公司,河南南阳474571 [4]大自然钢业集团有限公司,浙江温州325000

出　　处：《金属热处理》2024年第11期77-83,共7页Heat Treatment of Metals

摘　　要：中厚板Q890D钢作为工程机械用钢,其厚度方向组织与性能均匀性对于该钢服役过程中的安全性和寿命具有重要影响。针对国内某钢厂生产的50 mm厚Q890D钢调质板进行全厚度方向组织与性能分析,从显微组织、显微硬度、晶粒取向和缺陷等角度进行了差异化对比。结果表明,50 mm厚Q890D钢调质板有显著厚度截面效应,呈现出表面硬度高、心部硬度低特征,这种效应是组织和取向差异作用下的综合结果。调质处理后该钢板表面以回火板条马氏体为主,缺陷密度大,而心部以回火板条马氏体和少量贝氏体为主,缺陷密度小。此外,该钢板表面有明显的[001]择优取向,而心部却展现出不太明显的[101]择优取向。这种厚度截面效应与调质过程中的温度梯度有关,表面冷速大易于形成马氏体,而心部冷速偏慢易于形成贝氏体。表面处马氏体相变约束作用明显小于心部,故厚度方向呈现差异化择优取向。As a steel used in construction machinery,the uniformity of microstructure and properties along the thickness of Q890D steel medium-thick plate has an important influence on the safety and life of the steel during service.The microstructure and properties of 50 mm thick Q890D steel quenched and tempered plate from a domestic steel mill were analyzed along its thickness direction.The metallographic microstructure,microhardness,orientation distribution and defects at different positions along the thickness direction were analyzed.The results show that the 50 mm thick Q890D steel quenched and tempered plate has a significant thickness cross-section effect,showing high hardness at the surface and low hardness at the center,respectively,which is the comprehensive result by the difference of microstructure and orientation.After quenching and tempering,the surface of the steel is dominated by tempered lath martensite with high defect density,while the center is dominated by tempered lath martensite and a small amount of bainite with low defect density.In addition,the surface of the steel has a clear[001]preferred orientation,while the center of the plate shows a less obvious[101]preferred orientation.The thickness cross-section effect is related to the temperature gradient during the quenching and tempering process.Large cooling rate on the surface is easy to form martensite,while slow cooling rate in the center is easy to form bainite.The transformation constraint effect of martensite on the surface is obviously smaller than that in the center,so a differentiated preferred orientation is shown along the thickness direction.

关 键 词：Q890D钢 中厚板 调质 硬度 显微组织 取向 

分 类 号：TG142.1[一般工业技术—材料科学与工程]