工程科学学报，第38卷，第10期：1423-1428,2016年10月 Chinese Journal of Engineering,Vol.38,No.10:1423-1428,October 2016 D0l:10.13374/j.issn2095-9389.2016.10.011:http://journals..ustb.edu.cn 开轧温度对铌微合金化热成型钢氢致延迟开裂性能 的影响 程亚杰”，孙斌堂”，廖庆亮)四，范光龙”，张跃2) 1)北京科技大学材料科学与工程学院，北京1000832)北京科技大学新金属材料国家重点实验室，北京100083 ☒通信作者，E-mail:liao@ustb.cdu.cn 摘要通过动态充氢恒载荷、氢渗透等实验研究轧制工艺对铌合金化热成型钢的氢致延迟开裂性能的影响.随着开轧温 度从1000℃降低到950℃，热成型钢的氢扩散系数降低，氢致延迟开裂性能提高，耐腐蚀性能下降.透射电镜观察发现开轧 温度为1000℃时MX型析出相尺寸为30nm:开轧温度为950℃时热成型钢的MX型析出相尺寸为5m左右，可以观察到直 径为50mCr2C:析出相.作为氢陷阱的纳米析出相是提高实验钢氢致延迟开裂性能的主要因素.析出相不同的原因是开轧 温度为1000℃时MX型析出相发生熟化现象，进一步抑制Cr,C,的析出. 关键词热成型钢：铌：合金化：轧制温度；析出相：氢致延迟开裂 分类号TG111.91:TG142.1 Effect of initial rolling temperature on the hydrogen-induced delayed fracture of Nb alloyed hot stamping steel CHENG Ya-jie,SUN Bin-tang,LIAO Qing-Hiang,FAN Guang-long,ZHANG Yue) 1)School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China 2)State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing,Beijing 100083,China Corresponding author,E-mail:liao@ustb.edu.cn ABSTRACT The effect of initial rolling temperature on the hydrogen-induced delayed fracture resistance of Nb alloyed hot stamping steel was studied by the constant load test and the electrochemical hydrogen permeation method.When the initial rolling temperature drops from 1000 C to 950 C,the hydrogen diffusion coefficient and the corrosion resistance of the steel decrease,but the hydrogen-in- duced delayed fracture resistance increases.TEM test shows that when the initial rolling temperature is 1000C,the MX precipitated phase has an average size of 30nm,and the CrC precipitated phase can be observed with an average size of 100nm:when the initial rolling temperature is 950 C,the MX precipitated phase has an average size of 5 nm.The main reason leading to the improvement of delayed fracture resistance is the hydrogen trapping effect of the MX precipitated phase.The reason for the difference of precipitated phases is that a higher rolling start temperature will prompt the coarsening of the MX precipitated phase,which will suppress the pre- cipitation of the Cr,C:phase. KEY WORDS hot stamping steel:niobium:alloying:rolling temperature:precipitates:hydrogen-induced delayed cracking 轻量化和安全性是汽车发展的新方向，也是实现成型钢是指在钢加热到950℃保温奥氏体化，冲压模 节能减排，保护环境的重要途径.热成型钢的开发及 具一次完成淬火和成型两道工序，组织一般为板条马 在汽车上的应用是汽车实现轻量化的重要途径”.热 氏体，具有超高的强度和较好的韧性四.但是随着强 收稿日期：2016-12-14 基金项目：国家自然科学基金资助项目(51372020,51672026)工程科学学报，第 38 卷，第 10 期: 1423--1428，2016 年 10 月 Chinese Journal of Engineering，Vol． 38，No． 10: 1423--1428，October 2016 DOI: 10． 13374 /j． issn2095--9389． 2016． 10． 011; http: / /journals． ustb． edu． cn 开轧温度对铌微合金化热成型钢氢致延迟开裂性能 的影响 程亚杰1) ，孙斌堂2) ，廖庆亮1) ，范光龙1) ，张 跃1，2) 1) 北京科技大学材料科学与工程学院，北京 100083 2) 北京科技大学新金属材料国家重点实验室，北京 100083  通信作者，E-mail: liao@ ustb． edu． cn 摘 要 通过动态充氢恒载荷、氢渗透等实验研究轧制工艺对铌合金化热成型钢的氢致延迟开裂性能的影响． 随着开轧温 度从 1000 ℃降低到 950 ℃，热成型钢的氢扩散系数降低，氢致延迟开裂性能提高，耐腐蚀性能下降． 透射电镜观察发现开轧 温度为 1000 ℃时 MX 型析出相尺寸为 30 nm; 开轧温度为 950 ℃时热成型钢的 MX 型析出相尺寸为 5 nm 左右，可以观察到直 径为 50 nm Cr2C3析出相． 作为氢陷阱的纳米析出相是提高实验钢氢致延迟开裂性能的主要因素． 析出相不同的原因是开轧 温度为 1000 ℃时 MX 型析出相发生熟化现象，进一步抑制 Cr2C3的析出． 关键词 热成型钢; 铌; 合金化; 轧制温度; 析出相; 氢致延迟开裂 分类号 TG111. 91; TG142. 1 Effect of initial rolling temperature on the hydrogen-induced delayed fracture of Nb alloyed hot stamping steel CHENG Ya-jie1) ，SUN Bin-tang2) ，LIAO Qing-liang1)  ，FAN Guang-long1) ，ZHANG Yue1，2) 1) School of Materials Science and Engineering，University of Science and Technology Beijing，Beijing 100083，China 2) State Key Laboratory for Advanced Metals and Materials，University of Science and Technology Beijing，Beijing 100083，China  Corresponding author，E-mail: liao@ ustb． edu． cn ABSTＲACT The effect of initial rolling temperature on the hydrogen-induced delayed fracture resistance of Nb alloyed hot stamping steel was studied by the constant load test and the electrochemical hydrogen permeation method． When the initial rolling temperature drops from 1000 ℃ to 950 ℃，the hydrogen diffusion coefficient and the corrosion resistance of the steel decrease，but the hydrogen-in￾duced delayed fracture resistance increases． TEM test shows that when the initial rolling temperature is 1000 ℃，the MX precipitated phase has an average size of 30 nm，and the Cr2C3 precipitated phase can be observed with an average size of 100 nm; when the initial rolling temperature is 950 ℃，the MX precipitated phase has an average size of 5 nm． The main reason leading to the improvement of delayed fracture resistance is the hydrogen trapping effect of the MX precipitated phase． The reason for the difference of precipitated phases is that a higher rolling start temperature will prompt the coarsening of the MX precipitated phase，which will suppress the pre￾cipitation of the Cr2C3 phase． KEY WOＲDS hot stamping steel; niobium; alloying; rolling temperature; precipitates; hydrogen-induced delayed cracking 收稿日期: 2016--12--14 基金项目: 国家自然科学基金资助项目( 51372020，51672026) 轻量化和安全性是汽车发展的新方向，也是实现 节能减排，保护环境的重要途径． 热成型钢的开发及 在汽车上的应用是汽车实现轻量化的重要途径［1］． 热 成型钢是指在钢加热到 950 ℃ 保温奥氏体化，冲压模 具一次完成淬火和成型两道工序，组织一般为板条马 氏体，具有超高的强度和较好的韧性［2］． 但是随着强