Effect of annealing on corrosion resistance and mechanical properties of Cr–Fe–Ni–Co–Mo–Si–B amorphous coating

Cr–Fe–Ni–Co–Mo–Si–B amorphous coating was successfully prepared on 316 L steel using atmospheric plasma spraying (APS). The effects of different annealing temperatures on the crystallization process of amorphous coatings, thus on the corrosion resistance and mechanical properties of coatings were studied. The results indicated that heat treatment can increase the hardness of the amorphous coating by 12.5% and reduce the wear rate by 30%. In addition, compared to heat-treated coatings, the amorphous coating had the highest corrosion voltage (−0.506V) and lower corrosion current (5.609 × 10−6 A). The passivation film on the amorphous coating provided the best protection due to the relatively high content of Cr2O3. The molecular dynamics (MD) calculation results also indicated that the adsorption energy of hydrogen chloride molecules on Cr–Fe–Ni–Co–Mo–Si–B amorphous coating (−90.94 kcal/mol) was greater than that of 316 L (−293.03 kcal/mol).