基于纳米压痕试验的氢致双相不锈钢微力学性能变化

Hydrogen-induced micromechanical property evolution of duplex stainless steel based on nanoindentation

通过纳米压痕方法对氢致铁素体-奥氏体双相不锈钢中微观力学性能变化行为进行研究,试验选用2205双相不锈钢为研究对象,通过不同充氢时间下获得的铁素体相和奥氏体相的压痕载荷-位移曲线,分析了铁素体相和奥氏体相的纳米硬度变化规律。结果表明,铁素体相和奥氏体相的纳米硬度随充氢时间的增加而增加,表现出氢致硬化的现象,充氢3 h后两相的氢致硬化效果基本达到饱和状态,其中奥氏体相的氢致硬化程度明显高于铁素体相。研究结果揭示了铁素体相和奥氏体相氢致硬化规律的差异,并论证了纳米压痕方法在微观力学氢损伤方面的研究优势。

In this paper,the hydrogen-induced micromechanical property evolution of ferritic-austenitic duplex stainless steel was studied by nanoindentation and in situ hydrogen-charging method.The 2205 duplex stainless steel was selected as the research object in experiments,during which the nanohardness variation of ferrite and austenite was mainly analyzed,based on the obtained nanoindentation loaddisplacement curves under different hydrogen-charging time. The results show that the nanohardness of ferrite and austenite increases with hydrogen-charging time, presenting the hydrogen-induced hardening performance. After 3 hours hydrogen charging, the hydrogen-induced hardening effect of the two phases reaches saturation state, and the degree of increased nanohardness of austenite is higher than that of ferrite. The results show the hydrogen-induced hardening difference of ferrite and austenite, and demonstrate the research advantages of nanoindentation method in terms of characterizing hydrogen damage in the micro-scale.