Influence of Nitriding on the Microabrasion Wear Resistance of Supermartensitic Stainless Steel UNS S41426

Supermartensitic stainless steels (SMSSs) are corrosion-resistant alloys widely used in oil and gas applications, particularly as pipes and components in production columns. They represent a technical and economical alternative to traditional duplex and superduplex stainless steel, especially in Brazil, where SMSSs are domestically produced and offer lower costs with good properties. However, standard hardness limits imposed to prevent stress corrosion cracking may reduce their resistance to abrasive wear. In oil and gas extraction, solid particles are often present in the production fluids, leading to abrasive wear damage. In this context, low-temperature plasma nitriding is considered a promising surface treatment to enhance the wear resistance of SMSS components. This study investigates how plasma nitriding can improve the abrasive wear resistance of UNS S41426 forged steel components exposed to hydrocarbon flows containing fine sand particles in oil production systems. Three nitriding temperatures (350 °C, 400 °C, and 570 °C) were applied, and the resulting layers were evaluated through microabrasion tests using SiO2 and Al2O3 to simulate different abrasive severities. Wear performance was assessed based on crater morphology, wear coefficient, and dominant wear mechanisms. Expanded austenite layers formed at lower temperatures improved surface hardness and reduced wear coefficients under both abrasives. Conversely, the 570 °C treatment produced a thicker but brittle compound layer that performed well only under low-severity wear conditions. These findings provide valuable insights for extending the service life and improving the tribological performance of critical SMSS components used in oil and gas applications.