Mitigating High-Temperature Oxidation of PCrNi1MoA Steel through Cr/CrN Multilayer Coating Protection

This study systematically examines the high-temperature oxidation behavior of PCrNi1MoA steel in the temperature range from 600°C to 900°C, focusing on the comparative performance of bare substrates and those protected by a Cr/CrN multilayer coating. The uncoated steel exhibited increasing oxide scale spallation and degradation with elevated temperature, forming complex iron oxide-based scales that provided limited oxidation resistance. In contrast, the Cr/CrN-coated samples developed a compact Cr2O3 scale that effectively suppressed oxygen ingress and maintained a well-defined multilayer architecture even at 900°C. This enhanced performance also stems from the effect of a multilayer architecture that provides both effective diffusion barriers and interfacial compatibility. These results highlight the effectiveness of the Cr/CrN multilayer coating in mitigating the oxidation of cannon-grade steels and provide a viable surface engineering strategy for improving their durability in high-temperature environments.