The influence of hydrogen on the mechanical behavior of a quenched and tempered 42CrMo4 steel has been evaluated by means of high internal pressure fracture tests carried out on hydrogen precharged notched cylindrical specimens. The notched cylindrical specimens were precharged for 3 h time with 1.2 mA/cm in two different aqueous media: 1 M HSO added with 0.25 g/l AsO and 3.5% of NaCl solution. Hydraulic fracture tests were performed at different ramps of pressure: 7000, 220, 80, 60 and 30 MPa/h, respectively. Hydrogen damage was more marked when the acid aqueous medium (1 M HSO + 0.25 g/l AsO) was employed. In this case, a higher hydrogen concentration was introduced, leading to hydrogen decohesion micromechanisms (HEDE) near the notched region, especially when tests were performed at 60 MPa/h. Hydrogen embrittlement susceptibility is discussed in terms of the microstructural singularities and the operative fracture micromechanisms observed in each case.

中文翻译：

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电化学充电对高内压低合金回火马氏体钢氢脆敏感性的影响

通过对预充氢缺口圆柱形试样进行高内压断裂试验，评估了氢对调质 42CrMo4 钢机械性能的影响。带缺口的圆柱形样品在两种不同的水介质中以 1.2 mA/cm 预充电 3 小时：1 M HSO 添加了 0.25 g/l AsO 和 3.5% 的 NaCl 溶液。水力断裂试验在不同的压力梯度下进行：分别为7000、220、80、60和30 MPa/h。当使用酸性水介质（1 M HSO + 0.25 g/l AsO）时，氢损伤更加明显。在这种情况下，引入了更高的氢浓度，导致缺口区域附近出现氢脱聚微观机制 (HEDE)，特别是在 60 MPa/h 的压力下进行测试时。根据每种情况下观察到的微观结构奇点和操作断裂微观机制来讨论氢脆敏感性。