GH3039 nickel-based alloy, as a key material for thermocouple protection tubes, is susceptible to wear and oxidation failure in high-temperature kiln environment. To address this, boronized, chromized and borochromized coatings were prepared on GH3039 substrate, and the friction-wear properties and high-temperature oxidation resistance of both the substrate and the coatings were systematically characterized. The results show that the borochromized coating, benefiting from the synergistic effect of its relatively high surface hardness and the boric acid lubricating film formed during the wear process, reduces the wear rate by 84.07% (to 1.44 × 10−5 mm3·N−1·m−1). Meanwhile, it exhibits the optimal oxidation resistance due to its dense Cr-rich layer, which can inhibit oxygen diffusion and supply chromium for protective Cr2O3 film. After 100 h of oxidation at 950 °C, its oxidation weight gain is reduced by 78.68% compared with the boronized sample (to 1.20 mg/cm2).
Xiao et al. (Sun,) studied this question.