1900 MPa级热成形钢组织性能特征研究  

STUDY ON MICROSTRUCTURE AND PROPERTIES OF 1900 MPa HOT STAMPED STEEL

作　　者：李伟男 喻建林 唐小勇[2] 刘涛[2] 赵征志 Li Weinan;Yu Jianlin;Tang Xiaoyong;Liu Tao;Zhao Zhengzhi(Collaborative Innovation Center of Steel Technology, University of Science and Technology Beijing;Xinyu Iron and Steel Group Co.,Ltd)

机构地区：[1]北京科技大学钢铁共性技术协同创新中心,北京100083 [2]新余钢铁集团有限公司

出　　处：《河南冶金》2025年第1期19-23,38,共6页Henan Metallurgy

基　　金：江西省赣鄱俊才支持计划项目(20232BCJ22030)。

摘　　要：汽车的轻量化已成为其设计和制造的主要趋势。在众多轻量化手段中,采用高强度和超高强度钢是实现这一目标的关键方法。在传统热成形钢的基础上开发了1900 MPa级热成形钢。试验表明,在720℃稳定条件下进行14 h罩式退火的冷轧试样,其显微组织为准多边形的铁素体、块状的马氏体以及颗粒状的渗碳体,屈服强度为484 MPa,抗拉强度为590 MPa,总伸长率为28.9%。退火试样经不同奥氏体化温度(910℃、930℃、950℃)淬火后,微观结构转变为均匀的马氏体组织,并展现出优良的综合力学性能,其屈服强度范围为1024~1174 MPa,抗拉强度为1898~1935 MPa,总伸长率为7.5%~7.6%。其中,910℃淬火试样具有最高的抗拉强度,达到1935 MPa;屈服强度也相对较高,为1047 MPa;伸长率达到7.5%。通过微观组织分析,经910℃淬火的试样内部马氏体Block尺寸更加细小,拥有更高的KAM值和GND值。The automotive industry is moving towards lightweighting,which has become a major trend in automotive design and manufacturing.Among numerous lightweight measures,the use of high-strength and ultra high strength steel is the key method to achieve this goal.A 1900 MPa grade hot formed steel has been developed based on traditional hot formed steel.Experiments have shown that the microstructure of cold-rolled test steel subjected to 14 h bell annealing at 720℃is composed of quasi polygonal ferrite,blocky martensite and granular cementite.The yield strength is 484 MPa,the tensile strength is 590 MPa,and the total elongation is 28.9%.After quenching at different austenitization temperatures(910℃,930℃,950℃),the microstructure of the annealed test steel transforms into a uniform martensitic structure and exhibits excellent comprehensive mechanical properties.Its yield strength range is 1024~1174 MPa,tensile strength is 1898~1935 MPa,and total elongation is 7.5%~7.6%.Among them,the 910℃quenched test steel has the highest tensile strength,reaching 1935 MPa,with a relatively high yield strength of 1047 MPa and an elongation of 7.5%.Through microstructure analysis,it was found that the martensite block size inside the test steel quenched at 910℃was smaller,with higher KAM and GND values.

关 键 词：1900 MPa级热成形钢 淬火 马氏体 位错强化 

分 类 号：TG142.1[一般工业技术—材料科学与工程]