Duplex treatments are performed to promote an additional property to a previous surface treatment to improve wear and corrosion resistance of the material, like the DLC film (diamond-like carbon) deposited on nitriding or nitrocarburizing surfaces on the AISI 4340 steel. The purpose of this work is to study the effect of the duplex treatment (nitriding + DLC and nitrocarburizing + DLC film deposition) on the wear and corrosion resistance of AISI 4340 steel. The nitrocarburizing treatments by plasma were performed with 80% N₂ + 17% H₂ + 3% CH₄ at 400, 450, 500, 525 and 550 °C for 5 h. The nitriding treatment by plasma at 450 °C was performed with 80% N₂ + 20% H₂ for 5 h. The interlayer deposition was performed using hexamethyldisiloxane as a precursor. The deposition of DLC film was performed by DC-PECVD method using 90% CH₄ + 10% Ar at 200 °C for 2 h. The duplex treatment was performed at the optimum temperature of the nitrocarburizing process. Micro-abrasive wear tests by fixed ball, and corrosion tests showed that all material treated presented lower wear volume and higher corrosion resistance than untreated material, but the duplex treatments provided greater wear and corrosion resistance than that observed on materials treated with only one type of treatment, showing that duplex treatment improves surface resistance of the AISI 4340 steel. The nitrocarburizing + DLC duplex treatment presented greater wear and corrosion resistance than nitriding + DLC duplex treatment, evidencing the great positive effect of carbon added to the treatment.

进行双相处理是为了提高先前的表面处理的附加性能，以改善材料的耐磨性和耐腐蚀性，例如，沉积在AISI 4340钢氮化或氮碳共渗表面上的DLC膜（类金刚石碳）。这项工作的目的是研究双重处理（氮化+ DLC和氮碳共渗+ DLC膜沉积）对AISI 4340钢的耐磨性和耐蚀性的影响。在80、400、450、500、525和550°C下，用80％N ₂  + 17％H ₂  + 3％CH ₄进行等离子体氮碳共渗处理5小时。使用80％N ₂  + 20％H ₂在450°C下通过等离子体进行氮化处理5小时。使用六甲基二硅氧烷作为前体进行层间沉积。DLC膜的沉积通过DC-PECVD法使用90％CH _4进行。 在200°C下+ 10％Ar 2 h。在氮碳共渗工艺的最佳温度下进行双相处理。通过固定球进行的微磨料磨损测试和腐蚀测试表明，所有处理过的材料均比未处理的材料具有更低的磨损量和更高的耐腐蚀性，但是双相处理比仅使用一种类型的材料处理的材料具有更高的耐磨性和耐腐蚀性。处理，表明双相处理可改善AISI 4340钢的表面电阻。氮碳共渗+ DLC双相处理比氮化+ DLC双相处理具有更高的耐磨性和耐腐蚀性，证明了碳添加到处理中的巨大积极作用。