Design and production of spray-formed boron-modified stainless steels with high corrosion and wear resistance

Abstract

Wear and corrosion resistance are basic requirements of materials which withstand aggressive environments such as those found in the petrochemical industry. Stainless steels are interesting due to their combination of good mechanical properties and high corrosion resistance. When modified with boron, the corrosion resistant stainless steel matrix is reinforced with hard borides resistant to wear. Although the recent progress on the minor boron additions on the microstructure and properties of boron-modified stainless steels, studies on their impact on the wear and corrosion properties are limited. This research project aims to design different microstructures consisted of stainless steel matrix reinforced by hard borides, using spray forming to produce the final alloy. Different stainless steel grades are to be modified with minor boron additions in view to assure both high wear and corrosion resistance. Three master alloys will be considered: ferritic, austenitic, and duplex stainless steels. Their composition will be modified with boron based on thermodynamic calculations. Microstructure characterizations of the spray-formed boron-modified stainless steels will be performed to validate the thermodynamic calculations. Wear properties will be investigated by pin-on-disc tests. Different applied loads, sliding speeds, and wear distances will be considered. The galvanic and long-term corrosion resistance in acid chloride-rich media will be evaluated. At the end, it is expected to identify the better application for each microstructure based on its wear and corrosion properties. (AU)