Effect of Neutral Salt Spray Corrosion on Tribological Properties of SPS Sprayed NiCr-Cr3C2 Coatings

Abstract:

Ceramic phase increased NiCr-Cr3C2 coatings were prepared by HEPJet supersonic plasma spaying (SPS). The friction coefficients and wear loss for NiCr-Cr3C2 coating and Q235 steel pairs under dry and salt spray one week corrosion were measured using the UMT-3 friction and wear tester by line-contact reciprocating sliding. The morphology and element distribution of worn surfaces were examed and analyzed by using SEM, EDS respectively. The effects of salt spray corrosion environment on tribological properties of coatings were discussed. The result showed that, the wear mechanism of NiCr-Cr3C2 coatings was abrasive and adhesive wear, whereas under salt spray corrosion conditions, it became corrosion wear. The friction coefficient under salt spray corrosion conditions significantly reduced by 1/5, but the wear losses under salt spray corrosion conditions were more than that under dry friction conditions about 5 times, which demonstrates that the salt spray corrosion environment accelerated the deterioration of coating’s tribological properties and the corrosion resistance of coating remains to be further improved.

Key words:salt spray corrosion; SPS; nickel-chromium-based; friction and wear behavior