(1. 南昌航空大學(xué) 材料科學(xué)與工程學(xué)院，南昌 330063；
2. 南昌航空大學(xué) 江西省金屬材料微結(jié)構(gòu)調(diào)控重點實驗室，南昌 330063)
摘 要: 利用透射電鏡(TEM)、X射線衍射(XRD)、洛氏硬度、動電位極化曲線和交流阻抗等方法對15-5PH不銹鋼時效后的組織轉(zhuǎn)變、時效硬化行為及其在Cl-溶液中的耐蝕性能進行研究。結(jié)果表明：時效溫度較低(低于450 ℃) 時，析出的富Cu相與基體保持共格關(guān)系，其硬度和耐腐蝕性能都較高。當時效溫度達到550 ℃時，富Cu相長大，出現(xiàn)了逆變奧氏體，且隨時效時間的延長而增多，導(dǎo)致硬度下降，但耐蝕性能有所提高；當時效溫度升高至620 ℃時，富Cu相呈短棒狀，且失去與基體的共格關(guān)系，逆變奧氏體繼續(xù)增多，強化效應(yīng)完全消失，但耐蝕性能得到改善。
關(guān)鍵字: 15-5PH不銹鋼；富Cu相；逆變奧氏體；硬化行為；耐蝕性
（1. School of Material Science and Engineering, Nanchang Hangkong University, Nanchang 330063, China;
2. Key Laboratory for Microstructural Control of Metallic Materials of Jiangxi Province, Nanchang Hangkong University, Nanchang 330063, China）
Abstract:The microstructure transformation, aging hardening behavior and corrosion resistance of 15-5PH stainless steel were studied by XRD, TEM, HRC, polarization curve and electrochemical impedance spectroscopy. The results show that the hardness and corrosion resistance due to Cu-rich phase have coherent orientation relationship with matrix when the aging temperature is lower than 450℃. The Cu-rich phases coarsening and the reversed austenite are observed in the specimen, when the aging temperature reaches to 550 ℃. Moreover, the amount of reversed austenite increases with the increase of aging time. So, the hardness decreases but the corrosion resistance increases. When the aging temperature reaches 620 ℃, the Cu-rich phases exhibit elliptical shape and destroy the coherent relation with the martensite matrix, meanwhile, the reversed austenite continues to increase. As a result, the precipitation hardening effect disappears, however, the corrosion resistance is improved.
Key words: 15-5 PH stainless steel; Cu-rich phase; reversed austenite; hardening behavior; corrosion resistance
