摘要
A three-dimensional atom probe （3DAP） technique has been used to characterize the hydrogen dis- tribution on carbides for a high strength AISI 4140 steel. Direct evidence of H atoms trapped at the carbide/ferrite interfaces has been revealed by 3DAP mapping. Hydrogen is mainly trapped on car- bide/ferrite interfaces along the grain boundaries. Slow strain rate tensile （SSRT） testing shows that the AIS14140 steel is highly sensitive to hydrogen embrittlement. The corresponding ffactographic mor- phologies of hydrogen charged specimen exhibit brittle fracture feature. Combined with these results, it is proposed that the hydrogen trapping sites present in the grain boundaries are responsible for the hydrogen-induced intergranular fracture of AISI 4140. The direct observation of hydrogen distribution contributes to a better understanding of the mechanism of hydrogen embrittlement.
A three-dimensional atom probe （3DAP） technique has been used to characterize the hydrogen dis- tribution on carbides for a high strength AISI 4140 steel. Direct evidence of H atoms trapped at the carbide/ferrite interfaces has been revealed by 3DAP mapping. Hydrogen is mainly trapped on car- bide/ferrite interfaces along the grain boundaries. Slow strain rate tensile （SSRT） testing shows that the AIS14140 steel is highly sensitive to hydrogen embrittlement. The corresponding ffactographic mor- phologies of hydrogen charged specimen exhibit brittle fracture feature. Combined with these results, it is proposed that the hydrogen trapping sites present in the grain boundaries are responsible for the hydrogen-induced intergranular fracture of AISI 4140. The direct observation of hydrogen distribution contributes to a better understanding of the mechanism of hydrogen embrittlement.
基金
financially supported by the Joint Funds of the National Natural Science Foundation of China(Grant No.U1608257)
