Structural modifications and corrosion behavior of martensitic stainless steel nitrided by plasma immersion ion implantation

Abstract

Process window and mechanism of surface property enhancement of 9Cr18 steel using plasma immersion ion implantation J. Vac. Sci. Technol. B 17, 851 (1999) In this work we report a study of the structural modifications and corrosion behavior of martensitic stainless steels ͑MSS͒ nitrided by plasma immersion ion implantation ͑PI 3 ͒. The samples were characterized by x-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, photoemission electron spectroscopy, and potentiodynamic electrochemical measurements. Depending on the PI 3 treatment temperature, three different material property trends are observed. At lower implantation temperatures ͑e.g., 360°C͒, the material corrosion resistance is improved and a compact phase of -͑Fe, Cr͒ 3 N, without changes in the crystal morphology, is obtained. At intermediate temperatures ͑e.g., 430°C͒, CrN precipitates form principally at grain boundaries, leading to a degradation in the corrosion resistance compared to the original MSS material. At higher temperatures ͑e.g., 500°C͒, the relatively great mobility of the nitrogen and chromium in the matrix induced random precipitates of CrN, transforming the original martensitic phase into ␣-Fe ͑ferrite͒, and causing a further degradation in the corrosion resistance.

Martensitic Stainless Steels Low-temperature Nitriding: Dependence of Substrate Composition

“…For applications demanding high wear resistance the properties of such steels are frequently insufficient, so surface treatment like nitriding or carburizing can be applied to improve the component surface properties [1][2][3][4][5][6] . For this purpose, lowtemperature plasma-assisted techniques is among of the most studied techniques for this steel class.…”

Nitrogen Supersaturation Process in the AISI420 Martensitic Stainless Steels by Low Temperature Plasma Nitriding

“…5,6) Among various parameters such as the alloying elements, 7) the cathode setups, 8) the gas mixtures, 9) the nitriding times, 10) and the nitriding temperatures, 11,12) the holding temperature has the most significant impact on the nitriding processes as well as the mechanical and chemical properties of nitrided stainless steels.…”

Low-temperature plasma nitrocarburizing of the AISI 420 martensitic stainless steel: Microstructure and process kinetics

“…For example, AISI 420 martensitic stainless steel is commonly used in the fabrication of structural parts such as gears and shafts, automotive components, hydraulic turbine blades, oil and gas valves, pipes and chlorinated plastic injection molds, among others [1][2][3][4]. The large application field of martensitic stainless steels is mainly due to its ability of combining good mechanical properties and moderate corrosion resistance [5,6]. However, for some applications, it is necessary to improve the steel surface properties, which can be obtained by means of thermochemical process.…”