Determination of Mechanical and Corrosion Properties of Boride Coating on P91 Steel

Abstract

In many applications, even high-performance alloys have to be covered with protective coatings, providing higher corrosion and oxidation resistance, as compared to the alloy itself. This study investigates the feasibility to apply boron coatings on P91 steel by pack cementation process, to increase the steel durability in oxidative and corrosive environments, as well as its mechanical strength. Micro-indentation and the coating impact test were used to characterize the hardness and fatigue properties of the film respectively. The coating corrosion resistance versus the one of the uncoated P91 steel was tested in a salt spray chamber. The coating performance was characterized by optical and scanning electron microscopy to check the consistency of the coated and uncoated surfaces and the oxidation extend. The results show an increased film strength, good fatigue performance and adequate corrosion resistance.