回火温度对Nb、V合金化低合金高强度钢氢脆敏感性的影响  

Effect of tempering temperature on hydrogen embrittlement sensitivity of a low-alloy high-strength steel with Nb and V

作　　者：李晓亮 程晓英[1] 王兆丰 任毓文 曾繁宇 Li Xiaoliang;Cheng Xiaoying;Wang Zhaofeng;Ren Yuwen;Zeng Fanyu(Institute of Materials,Shanghai University,Shanghai 200072,China)

机构地区：[1]上海大学材料研究所,上海200072

出　　处：《金属热处理》2024年第3期7-14,共8页Heat Treatment of Metals

基　　金：国家自然科学基金(51871145)。

摘　　要：为了提高钢强度的同时降低氢脆敏感性,研制了一种同时添加0.11wt%Nb和0.55wt%V元素的低合金高强度钢。运用光学显微镜(OM)、X射线衍射仪(XRD)和透射电镜(TEM)等表征手段,并通过双电解池氢渗透技术和慢应变速率拉伸试验,研究了3种不同回火温度(560、600、640℃)对试验钢显微组织、氢扩散行为和氢脆敏感性的影响。结果表明,随着回火温度的升高,铁素体晶粒尺寸增大,位错密度降低,弥散析出的碳化物粗化,因此抗拉强度降低而伸长率增加;另一方面,可逆氢陷阱密度降低,扩散激活能降低,氢扩散系数增大,因此氢脆敏感性降低。In order to improve strength and simultaneously reduce hydrogen embrittlement sensitivity,a low-alloy high-strength steel with 0.11wt%Nb and 0.55wt%V was developed.The effect of three different tempering temperatures(560,600,640℃)on the microstructure,hydrogen diffusion behavior and hydrogen embrittlement sensitivity of the tested steel was characterized and studied by using optical microscope(OM),X-ray diffraction(XRD),transmission electron microscope(TEM),hydrogen permeation technique of double electrolytic cells and slow strain rate tensile test.The results show that with the increase of tempering temperature,the ferrite grain size increases while the dislocation density reduces,and the carbides precipitated become coarse,hence the tensile strength decreases and the elongation increases.Meanwhile,with the increase of tempering temperature,the density of hydrogen reversible traps reduces and the activation energy of hydrogen diffusion decreases,as well as the hydrogen diffusion coefficient increases,hence the hydrogen embrittlement sensitivity becomes lower.

关 键 词：低合金高强度钢 回火温度 位错密度 氢扩散 氢脆 

分 类 号：TG113.25[金属学及工艺—物理冶金]