压力容器用钢氢蚀后组织与力学性能研究

Study of Mechanical Properties and Structures for Pressure Vessel Steels After Hydrogen Attack

研究了氢腐蚀后２０Ｇ和１５ＣｒＭｏ钢力学性能与显微组织的变化；并用扫描电镜分析了拉伸断口的特征．结果表明：２０Ｇ钢力学性能的下降是由于氢蚀造成珠光体的减少和裂纹的出现；并使断裂机制发生了韧性向脆性的转变．１５ＣｒＭｏ钢具有较强的抗氢腐蚀能力，力学性能的变化是因为严重的表面脱碳造成。抗拉强度的变化对整个氢蚀过程都敏感；而延伸率的变化仅在氢蚀前期敏感。

The mechanical properties of 20G and 15CrMo steels with hydrogen attack have been investigated. The Microstructures and the morphologies or tensile fracture surfaces after hydrogn attack have been observed respectively by optical microscopy and scanning electron microscopy. The results showed that the reduction of mechanical properties for 20G steel resulted from decreasing of pearlite amount and existing of as caused by hydrogen attack. The transition of fracture mechanism for 20G steel occured from tough mode to brittle mode. The 15CrMo steel had high resistance to hydrogen attack and the lowering of its mechanical properties is due to severe decarbonization.The tensile strength is susceptible to the whole stage of hydrogen attack and elongation only to the previous hydrogen attack.