In this paper, microstructure characteristics and phase transitions of Fe-19 wt%Cr-9 wt%Ni nanocrystalline alloy are comprehensively studied during the mechanical alloying and hot pressing sintering processes. Corrosion resistance of the sintered Fe-19 wt%Cr-9 wt%Ni nanocrystalline alloy samples is further analyzed. During the mechanical alloying process, Fe-19 wt%Cr-9 wt%Ni nanocrystalline alloy powders mainly composed of metastable ferrite phase are obtained after mechanical alloying for 8, 16 and 24 h, respectively. In the subsequent hot pressing sintering process, the phase transitions (from ferrite to austenite) occur from 650 to 750 °C for Fe-19 wt%Cr-9 wt%Ni alloy powders milled for 24 h. When the sintering temperature is raised to 1050 °C for 1 h, the ferrite phase has transformed into austenite phase completely, and the obtained grain size of sintered Fe-19 wt%Cr-9 wt%Ni alloy is around 40 nm. Electrochemistry test of the sintered Fe-19 wt%Cr-9 wt%Ni alloy has been operated in 0.5 mol L⁻¹ H₂SO₄ solution to show the corrosion resistance properties. Results show that the sintered Fe-19 wt%Cr-9 wt%Ni alloy exhibits excellent corrosion resistance, which is proved by higher self-corrosion potential, lower self-corrosion current density and larger capacitive reactance, compared with that of commercial 304 stainless steel.

本文对Fe-19wt％Cr-9wt％Ni纳米晶合金在机械合金化和热压烧结过程中的微观结构特征和相变进行了综合研究。进一步分析了Fe-19 wt％Cr-9 wt％Ni纳米晶合金样品的耐腐蚀性。在机械合金化过程中，经过机械合金化8、16和24 h后，分别获得了主要由亚稳态铁素体相组成的Fe-19 wt％Cr-9 wt％Ni纳米晶合金粉末。在随后的热压烧结过程中，对于研磨24小时的Fe-19 wt％Cr-9 wt％Ni合金粉末，相变（从铁素体到奥氏体）在650至750°C时发生。当烧结温度升至1050°C 1 h时，铁素体相已完全转变为奥氏体相，Fe-19wt％Cr-9wt％Ni合金的烧结后晶粒尺寸约为40nm。烧结Fe-19 wt％Cr-9 wt％Ni合金的电化学测试已在0.5 mol L中进行^-1 H ₂ SO ₄溶液具有耐腐蚀性。结果表明，与市售304不锈钢相比，烧结的Fe-19 wt％Cr-9 wt％Ni合金具有优良的耐蚀性，这可由较高的自腐蚀电位，较低的自腐蚀电流密度和较大的电抗来证明。钢。