摘要
In order to improve surface hardness and corrosion resistant property of 17-4PH martensitic stainless steel, the steel was plasma nitrocarburized at 560 ℃ for 2-4 h in a gas mixture of nitrogen, hydrogenand ethanol with rare earths （RE） addition. The experimental results showed that the modified layer was characterized by a compound layer containing two distinct zones （i.e. out ~dark zone＇ and inner ＇white zone＇）. The inner ＇white zone＇ was almost a precipitation free zone and had high hardness as well as good corrosion resistance. An- odic polarization test results showed that the specimens plasma nitrocarburized with RE addition had good corrosion resistance resulted mainly from their higher corrosion potentials, lower corrosion current densities and larger passive regions as compared with those of the un- treated one.
In order to improve surface hardness and corrosion resistant property of 17-4PH martensitic stainless steel, the steel was plasma nitrocarburized at 560 ℃ for 2-4 h in a gas mixture of nitrogen, hydrogenand ethanol with rare earths （RE） addition. The experimental results showed that the modified layer was characterized by a compound layer containing two distinct zones （i.e. out ~dark zone＇ and inner ＇white zone＇）. The inner ＇white zone＇ was almost a precipitation free zone and had high hardness as well as good corrosion resistance. An- odic polarization test results showed that the specimens plasma nitrocarburized with RE addition had good corrosion resistance resulted mainly from their higher corrosion potentials, lower corrosion current densities and larger passive regions as compared with those of the un- treated one.
基金
Project supported by National Natural Science Foundation of China(51071061,11176011)
Heilongjiang Postdoctoral Subsidies(LBH-Z10199)
Fundamental Research Funds for the Central Universities(HEUCFR1129)
China Postdoctoral Science Foundation(20110491026)
