Work

Influence of plasma conditions and surface finish on wear and corrosion behaviour of nitrocarburized AISI 316 L

Year: 2025

Type: article

Abstract: The study examines wear and corrosion resistance of expanded austenite layers on AISI 316 L, produced through a modified plasma nitrocarburizing (PNC) process utilizing a solid carbon precursor. Thereby, the generated reactive HCN allows for two adjustable PNC modes: direct glow and afterglow. The work investigates the effects of these PNC modes on polished and ground surfaces subjected to identical treatments (430 °C, 4 h, N 2 -H 2 plasma) using scanning electron microscopy, glow discharge optical emission spectroscopy , X-ray diffraction, hardness measurements, pin-on-disc tests against Al 2 O 3 , salt spray tests, and electrochemical polarization in 3.5 wt% NaCl solution. Significant differences were observed between the two PNC modes regarding layer modification and service behaviour. The direct glow PNC mode, involving both HCN gas-phase reactions and N ions (N 2 + , N + ) from the plasma-activated surface, resulted in a higher nitrogen diffusion depth and a higher nitrogen content, leading to increased surface hardness and reduced wear volume loss three times lower than that of the afterglow mode. However, the high nitrogen input caused surface cracks, negatively impacting corrosion resistance for both surface finish types. In contrast, the afterglow PNC mode, which relies solely on HCN gas-phase reactions, resulted in lower N content and N diffusion depth, still exhibiting wear loss ten times lower than the untreated steel, and, however, an undisturbed morphology without cracks. Electrochemical tests revealed that only polished samples showed a quasi-passive zone and superior corrosion resistance, highlighting the significant influence of surface conditions prior to PNC treatment, particularly in the afterglow mode.

Source: Surface and Coatings Technology

DOI: 10.1016/j.surfcoat.2025.132081

Authors: Eugenia L. Dalibón, Saeed M. Jafarpour, Anke Dalke, Horst Biermann, Sonia P. Brühl

Institutions: National Technological University, TU Bergakademie Freiberg, Consejo Nacional de Investigaciones Científicas y Técnicas

Language: English

Topic: Surface Treatment and Coatings

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,880

Funders: Universidad Tecnológica Nacional, Deutsche Forschungsgemeinschaft, Korea Institute of Industrial Technology, Instituto Nacional de Tecnología Industrial