汽车用780MPa级别双相钢氢致延迟开裂行为的研究  

Research on Hydrogen Induced Delayed Cracking Behavior of 780MPa Grade Dual Phase Steel for Automotive

作　　者：谢春乾 王刚[2] 韩赟[1,3] 邝霜 刘华赛[1,3] 姜英花 滕华湘[1,3] 陈凌峰 XIE Chunqian;WANG Gang;HAN Yun;KUANG Shuang;LIU Huasai;JIANG Yinghua;TENG Huaxiang;CHEN Lingfeng(Shougang Research Institute of Technology,Beijing 100043,China;Dongfeng Peugeot Citroen Automobile Company LTD,Wuhan 430056,China;Beijing Key Laboratory of Green Recyclable Process for Iron &steel Production Technology, Beijing 100043,China)

机构地区：[1]首钢技术研究院,北京100043 [2]神龙汽车有限公司,湖北武汉430056 [3]绿色可循环钢铁流程北京市重点实验室,北京100043

出　　处：《热加工工艺》2018年第22期74-77,共4页Hot Working Technology

摘　　要：采用电化学充氢、慢拉伸试验、TDS分析以及SEM等方法对汽车用780 MPa级别双相钢(DP780)的氢致延迟开裂行为进行研究。结果发现,DP780的氢扩散系数为5.79×10-7cm^2/s。随着充氢电流密度从0 mA/cm^2增加到8mA/cm^2,试样内部氢含量从0.78 ppm增加到1.47 ppm,抗拉强度从802 MPa降低到758 MPa,氢脆敏感指数I_σ为5.49%。随内部氢含量的增加,DP780氢致开裂敏感性增加较小;同时断口形貌由韧性向脆性转变。The hydrogen induced delayed cracking behavior of 780 MPa grade dual phase steel for automotive was studied by electrochemical hydrogen charging, slow tensile test, TDS analysis and scanning electron microscope. The results show that the hydrogen diffusion coefficient of DP780 is 5.79 ×10-7 cm^2/s. And the hydrogen concentration in the samples increases from 0.78 ppm to 1.47 ppm, and tensile strength decreases from 802 MPa to 758 MPa,and the Hydrogen embrittlement sensitivity index I_σ is 5.49% when the hydrogen charging current density increases from 0 to 8 mA/cm^2. The hydrogen embrittlement sensitivity of DP780 increases a little with the increase of hydrogen content in the samples. And the fracture morphology changes from ductile fracture to brittle fracture.

关 键 词：汽车用双相钢 氢 延迟开裂 

分 类 号：TG142[一般工业技术—材料科学与工程]