1000 MPa级别超高强钢延迟开裂机理的研究  

Study on delayed cracking mechanism for ultra-high strength steel of 1000 MPa grade

作　　者：万荣春[1,2] 付立铭[2] 王学双 曹宝山 龚勋 Wang Rongchun;Fu Liming;Wang Xueshuang;Cao Baoshan;Gong Xun(Materials Engineering Department,Bohai Shipbuilding Vocational College,Huludao 125105,China;School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;China FAW Group Corporation,Changchun 130011,China;Liaoning Shunda Machinery Manufacturing(Group)Co.,Ltd.,Huludao 125004,China;People′s Government of Longgang District,Huludao City,Huludao 125001,China)

机构地区：[1]渤海船舶职业学院材料工程系,辽宁葫芦岛125105 [2]上海交通大学材料科学与工程学院,上海200240 [3]中国第一汽车集团公司,吉林长春130011 [4]辽宁顺达机械制造(集团)有限公司,辽宁葫芦岛125004 [5]葫芦岛市龙港区人民政府,辽宁葫芦岛125001

出　　处：《锻压技术》2023年第8期238-242,共5页Forging & Stamping Technology

基　　金：辽宁省教育厅2021年度科学研究经费项目(LJKZ1277)。

摘　　要：利用U形弯曲试验、动态充氢恒载荷试验和氢渗透试验研究了3种1000 MPa级别超高强钢的氢致延迟开裂性能。U形弯曲试验和动态充氢恒载荷试验结果表明,3种试验钢的氢致延迟开裂敏感性由高到低依次为:B钢>A钢>C钢。氢渗透试验结果表明,3种试验钢的氢表观扩散系数由低到高依次为:B钢>A钢>C钢。3种1000 MPa级别超高强钢的延迟开裂机理为:随着钢的强度提高,钢中氢陷阱浓度越高,钢的氢表观扩散系数下降,同时配合环境中氢浓度的变化,钢中氢浓度势必提高,一旦氢浓度达到延迟开裂临界氢浓度C0,试验钢即会出现氢致延迟开裂现象。超高强钢延迟开裂的两个重要影响因素为钢中氢陷阱浓度和环境中氢浓度。The hydrogen-induced delayed cracking properties for three kinds of ultra-high strength steels of 1000 MPa grade were studied by U-shaped bending test,dynamic hydrogen filling and constant load test and hydrogen permeation test.The results of U-shaped bending test and dynamic hydrogen filling and constant load test show that the hydrogen-induced delayed cracking sensitivity of the three test steels from high to low is B steel>A steel>C steel,respectively.The results of hydrogen permeation test show that the hydrogen apparent diffusion coefficients of the three test steels from low to high is B steel>A steel>C steel,respectively.The delayed cracking mechanism of the three ultra-high strength steels of 1000 MPa grade is as follows:with the increasing of steel strength,the hydrogen trap concentration in the steel increases,and the hydrogen apparent diffusion coefficient of the steel decreases.At the same time,with the change of hydrogen concentration in the environment,the hydrogen concentration in the steel is bound to increase.Once the hydrogen concentration reaches the critical hydrogen concentration C0 for delayed cracking,the hydrogen-induced delayed cracking appears in the test steel.Two important factors affecting the delayed cracking of ultra-high strength steel are the hydrogen trap concentration in the steel and the hydrogen concentration in the environment.

关 键 词：超高强钢 延迟开裂 氢渗透 门槛应力 氢浓度 

分 类 号：TG111.91[金属学及工艺—物理冶金]