Effects of H content on the tensile properties and fracture behavior of SA508-Ⅲsteel  

作　　者：Jia-hua Liu Lei Wang Yang Liu Xiu Song Jiong Luo Dan Yuan 

机构地区：[1]Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University

出　　处：《International Journal of Minerals,Metallurgy and Materials》2015年第8期820-828,共9页矿物冶金与材料学报（英文版）

基　　金：financially supported by the Major State Basic Research Development Program of China (No. 2011CB610506);the National Natural Science Foundation of China (Nos. 51371044 and 51171039);the Fundamental Research Fund for the Central Universities, China (No. N130410001)

摘　　要：SA508-Ⅲ steel was charged with different hydrogen(H) contents using a high-pressure thermal charging method to study the effects of H content on the tensile properties and evaluate the H embrittlement behavior of the steel. The results indicate that the ultimate tensile strength remains nearly unchanged with the addition of H. In contrast, the yielding strength slightly increases, and the elongation significantly decreases with increasing H content, especially at concentrations exceeding 5.6 × 10-6. On the basis of fractographic analysis, it is clear that the addition of H changes the fracture mode from microvoid coalescence to a mixture of river patterns and dimples. Carbides are strong traps for H; thus, the H atoms easily migrate in the form of Cottrell atmosphere toward the carbides following moving dislocations during tensile deformation. In addition, stress-induced H atoms accumulate at the interface between carbides and the matrix after necking under three-dimensional stress, which weakens the interfacial bonding force. Consequently, when the local H concentration reaches a critical value, microcracks occur at the interface, resulting in fracture.SA508-Ⅲ steel was charged with different hydrogen(H) contents using a high-pressure thermal charging method to study the effects of H content on the tensile properties and evaluate the H embrittlement behavior of the steel. The results indicate that the ultimate tensile strength remains nearly unchanged with the addition of H. In contrast, the yielding strength slightly increases, and the elongation significantly decreases with increasing H content, especially at concentrations exceeding 5.6 × 10-6. On the basis of fractographic analysis, it is clear that the addition of H changes the fracture mode from microvoid coalescence to a mixture of river patterns and dimples. Carbides are strong traps for H; thus, the H atoms easily migrate in the form of Cottrell atmosphere toward the carbides following moving dislocations during tensile deformation. In addition, stress-induced H atoms accumulate at the interface between carbides and the matrix after necking under three-dimensional stress, which weakens the interfacial bonding force. Consequently, when the local H concentration reaches a critical value, microcracks occur at the interface, resulting in fracture.

关 键 词：stainless steel tensile properties FRACTURE hydrog 

分 类 号：TG142.1[一般工业技术—材料科学与工程]