Abstract
Low temperature plasma carburizing treatment of austenitic stainless steels is a carbon surface diffusion process for a surface hardness and corrosion and wear resistance. The process is carried out by introducing a mixture of carbon-containing gases and through the use of low temperatures the resulting cemented layer usually contains a single phase of supersaturated austenite with carbon – S-phase. For the present investigation, austenitic stainless steels AISI 316L and 304 were plasma cemented for 8 hours in the gas mixture containing 7.5% CH4 in H2, with a pressure of 500 Pa, at temperatures of 375 oC and 450 oC. The phases formed were determined by X-ray diffraction. The corrosion resistance was evaluated through immersion tests over time and cyclic voltammetry. The results indicate that there was no formation of compounds (carbides) in the cemented layer for both steels at any of the temperatures and there was a corrosion resistance improvement. Keywords: plasma carburizing, AISI 304, AISI 316L, corrosion.
Highlights
Austenitic stainless steels have excellent corrosion resistance, high toughness and good workability and are widely used in the chemical, food and automotive processing industries, medical instruments and pharmaceutical equipment [1-3], as well as in orthopedic implants - in the case of AISI 316L steel [4-6]
Austenitic stainless steels AISI 316L and 304 were plasma cemented for 8 hours in the gas mixture containing 7.5% CH4 in H2, with a pressure of 500 Pa, at temperatures of 375 oC and 450 oC
The results indicate that there was no formation of compounds in the cemented layer for both steels at any of the temperatures and there was a corrosion resistance improvement
Summary
Austenitic stainless steels have excellent corrosion resistance, high toughness and good workability and are widely used in the chemical, food and automotive processing industries, medical instruments and pharmaceutical equipment [1-3], as well as in orthopedic implants - in the case of AISI 316L steel [4-6]. The influence of plasma carburizing - performed on an equipment used for plasma nitriding - in the surface hardness and corrosion resistance of AISI 316L and 304 austenitic stainless steels was investigated using a gas mixture composed of methane in hydrogen at two low treatment temperatures in order to avoid the precipitation of chromium carbides in the cemented layer Analysis techniques such as metallographic, vickers microhardness, phase determination by X-ray diffraction, immersion tests and cyclic voltammetry were used to characterize the corrosion resistance in simulated physiological solution At the same time, with the characterization and qualification of these layers, the objective is to obtain suitable plasma carburizing parameters to obtain layers with a maximum depth and with good characteristics of resistance to wear and corrosion, aiming at direct application in the petrochemical industry, food, pharmaceutical, among others. GOBBI, S.J.; GOBBI, V.J.; REINKE, G. revista Matéria, v.25, n.2, 2020
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
