Enhanced Wear Resistance and Corrosion Resistance of 304 Austenitic Stainless Steel by Duplex Surface Treatment

Duplex surface treatment (DST) is performed on 304 austenitic stainless steel (304ss) by Ni/Al2O3-coating pretreatment and atmospheric gas nitriding at 400 degrees C and below. The microstructure, microhardness, wear resistance, and corrosion resistance of the samples are investigated. Microhardness significantly increases to 853.66 +/- 39.76 HV0.05 due to a continuous nitrided layer that is formed on the DST 304ss at 400 degrees C. Compared with the single nitrided sample, the wear volume loss of the surface and nitrided layer of DST 304ss at 400 degrees C decreases by 92.0% and 97.2%, respectively. The obvious pitting corrosion phenomenon is presented on the surface of the single nitrided 304ss, while not on the nitrided layer of DST 304ss at 400 degrees C. The results show that the DST realizes the low-temperature nitriding of 304ss and effectively improves the microhardness, wear resistance, and corrosion resistance of 304ss. The Ni/Al2O3-coating pretreatment is expected to develop into a new type, low-cost, and efficient method to promote nitriding.

Automated summary

Duplex surface treatment of 304 austenitic stainless steel using Ni/Al2O3-coating pretreatment and atmospheric gas nitriding at temperatures below 400 degrees C significantly improves microhardness, wear resistance, and corrosion resistance.