Enhanced corrosion behavior of selective laser melting S136 mould steel reinforced with nano-TiB2

Abstract

The S136 mould steel matrix with varying mass fractions of TiB2 (0–2.5 wt%) were produced by selective laser melting (SLM). This study mainly focused on the influence of TiB2 content on the microstructure and corrosion property of the S136 composites in detail. The electrochemical method and weight loss test in the 3.5 wt% NaCl solution and 6 wt% FeCl3 solution were conducted to determine the corrosion resistance of the composites. Results demonstrated that the SLM 0.5 wt% TiB2/S136 composites possesses higher corrosion and pitting potentials as well as lower corrosion current density and weight loss compared to that of other samples owing to the existence of the finer grains and TiO2 passive film. Furthermore, the corrosion property of the composites decreased with the gradually increasing TiB2 content associating with more defects and galvanic cells, which was detrimental to the corrosion property. Herein, the corrosion mechanism of the SLM TiB2/S136 composites was also deeply discussed in this paper.