Tribocorrosion of CrN coatings on different steel substrates

Abstract

In this paper, CrN coatings were deposited on AISI 1045 steel, AISI H13 steel, and AISI 2205 duplex stainless steel substrates using arc ion plating. The effects of substrate characteristics on the hardcoated sample properties, especially tribocorrosion performance were investigated systematically. The results show that there were little differences in the surface morphology, crystalline structure as well as nanohardness among the three hardcoated samples. Compared with the bare substrates, the electrochemical properties of 1045-CrN and H13-CrN in 3.5 wt% NaCl solution were significantly improved with the Icorr values of 2.10 × 10−6 A·cm−2 and 9.63 × 10−7 A·cm−2, respectively, but still worse than that of 2205-CrN specimen (1.84 × 10−8 A·cm−2). The Ecorr of 2205-CrN was over 200 mV higher than those of 1045-CrN and H13-CrN. In addition, 2205-CrN displayed the highest Rct value of 1.953 × 106 Ω·cm2, which was enhanced by two orders of magnitude compared to the other two specimens owing to the excellent corrosion resistance of AISI 2205 steel substrate. The tribocorrosion rates of the three hardcoated specimens in 3.5 wt% NaCl solution were significantly reduced compared with their underlying substrates (by 70 %, 36 %, and 85 % for 1045-CrN, H13-CrN, and 2205-CrN, respectively). The 2205-CrN specimen displayed the best tribocorrosion performance with the rate of 2.51 × 10−6 mm3·N−1·m−1. The tribocorrosion mechanisms of CrN coatings deposited on carbon and stainless steels were also discussed. Mutual promotion effect of corrosion and wear was confirmed for CrN-coated carbon steels, while a negative synergistic effect was observed from the CrN-coated stainless steel substrate.