Abstract The mechanical performance and electrochemical stability in simulated body fluid (SBF) of a lightweight Fe-30Mn-10Al-1C (in wt.%) alloy after gas nitridation were investigated. The gas nitriding process was performed at 550 °C for 5 h under pure NH3 atmosphere. The nitrided layer was ∼45 μm-thick and consisted predominantly of fine AlN. The surface microhardness, ultimate tensile strength, yield strength, and elongation of the present gas-nitrided alloy are 1814 Hv, 1078 MPa, 1024 MPa, and 77%, respectively. The corrosion tests in SBF showed that the gas-nitrided alloy exhibited a corrosion current density (Icorr) of 5.0 × 10−9 A/cm2, a pitting corrosion current density (Ipit) of 5.1 × 10−7 A/cm2, and a passivation region with ΔE (≡Ep − Ecorr) ≈ +1804 mV, respectively, which are substantially better than those obtained in the plasma-nitrided and hydroxyapatite-coated 316L stainless steel. The results demonstrated that the present gas-nitrided alloy having an excellent combination of strength, ductility and corrosion resistance is a promising candidate to replace 316L stainless steel for medical implants.

中文翻译：

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气体氮化FeMnAlC合金在模拟体液中的力学行为和电化学稳定性

摘要 研究了气体氮化后轻质 Fe-30Mn-10Al-1C（重量百分比）合金在模拟体液（SBF）中的机械性能和电化学稳定性。气体渗氮过程在纯 NH3 气氛下在 550°C 下进行 5 小时。氮化层约 45 μm 厚，主要由细小的 AlN 组成。该气体氮化合金的表面显微硬度、极限抗拉强度、屈服强度和伸长率分别为 1814 Hv、1078 MPa、1024 MPa 和 77%。SBF 腐蚀试验表明，气体氮化合金的腐蚀电流密度 (Icorr) 为 5.0 × 10−9 A/cm2，点蚀电流密度 (Ipit) 为 5.1 × 10−7 A/cm2，以及钝化区分别为 ΔE (≡Ep − Ecorr) ≈ +1804 mV，明显优于等离子氮化和羟基磷灰石涂层的 316L 不锈钢。结果表明，本发明的气体氮化合金具有优异的强度、延展性和耐腐蚀性，是替代 316L 不锈钢用于医疗植入物的有希望的候选材料。