In this study, the effects of a boronizing treatment on the corrosion and wear behaviors of AISI 316L austenitic stainless steel (AISI 316L) were examined. The corrosion behavior of the boronized samples was studied via electrochemical methods in a simulation body fluid (SBF) and the wear behavior was examined using the ball-on-disk wear method. It was observed that the boride layer that formed on the AISI 316L surface had a flat and smooth morphology. Furthermore, X-ray diffraction analyses show that the boride layer contained FeB, Fe2B, CrB, Cr2B, NiB, and Ni2B phases. Boride layer thickness increased with an increasing boronizing temperature and time. The boronizing treatment also increased the surface hardness of the AISI 316L. Although there was no positive effect of the coating on the corrosion resistance in the SBF medium. Furthermore, a decrease in the friction coefficient was recorded for the boronized AISI 316L. As the boronizing temperature increased, the wear rate decreased in both dry and wet mediums. As a result, the boronizing treatment contributed positively to the wear resistance by increasing the surface hardness and by decreasing the friction coefficient of the AISI 316L.

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Corrosion studies were conducted for martensitic carbon steels in 5 wt% NaCl brine solutions at 4°C and 10 MPa (1,450 psi). These studies simulated different subsurface environments relevant to Arctic drilling. Here, two high-strength martensitic carbon steels, S-135 and UD-165, were studied in three different environments: (1) a CO 2-NaCl-H 2 O solution with a CO 2 :H 2 O molar ratio of 0.312 in the whole system, (2) an H 2 S-NaCl-H 2 O solution with an H 2 S:H 2 O molar ratio of 3.12 × 10 −4 , and (3) a CO 2-H 2 S-NaCl-H 2 O solution with the same acid gas to water ratios as environments 1 and 2. Results from the CO 2 +H 2 S mixed environment indicated that sour corrosion mechanism was dominant when the CO 2 :H 2 S molar ratio was 1,000. This impact of a small amount of H 2 S on the corrosion mechanism could be attributed to the specific adsorption of H 2 S on the steel surface. Electrochemical and mass loss measurements showed a distinct drop in the corrosion rate (CR) by more than one order of magnitude when transitioning from sweet to sour corrosion. This inhibiting effect on CR was attributed to the formation of a protective sulfide thin film. Tafel analyses of the anodic reaction showed that the Bockris mechanism was unlikely in the conditions tested. When comparisons were made between modeled and experimental CRs, good agreement was found in the CO 2-only and H 2 S-only environments, but not in the CO 2 +H 2 S environment.

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