到目前为止,对Ⅱ型试样的氢致开裂和应力腐蚀还没有进行深入的研究。本文用超高强钢Ⅱ型缺口试样,研究Ⅱ型试样能否产生氢致开裂,研究氢致裂纹的形核位置及方向,从而加深了对氢致开裂机理的研究。同时,用有限元8节点等参元法计算了缺口前端的应力场,并用之对实验结果进行了定量分析。实验过程超高强度钢34CrNi3MoA成分为(wt-％):C=0.33,Si=0.25,Mn=0.67,Cr=0.93,Ni=2.80,Mo=0.34,其余为Fe。试样加工 Up to now, there has not been any further study on hydrogen induced cracking and stress corrosion of Type II specimens. In this paper, Ⅱ type notched specimens of ultra-high strength steel were used to study whether hydrogen-induced cracking could be induced on type Ⅱ specimens and the nucleation sites and directions of hydrogen-induced cracking were studied. Thus, the mechanism of hydrogen induced cracking was deepened. At the same time, the finite element 8-node isoparametric element method was used to calculate the stress field at the front of the notch, and the experimental results were quantitatively analyzed. The experimental process of ultra high strength steel 34CrNi3MoA composition (wt -%): C = 0.33, Si = 0.25, Mn = 0.67, Cr = 0.93, Ni = 2.80, Mo = 0.34, the rest is Fe. Sample processing