Influence of Boriding Treatment on the Oxidation Resistance of the AISI H13 Tool Steel

The use of surface layers with high hardness in tool steels, such as borides (1400-1800 HV) can extend the life of components such as moulds and dies. In this work, samples of AISI H13 tool steel for hot work were borided by pack cementation process which produced uniform and high hardness layers. These samples were then subjected to the quasi-isothermal oxidation testing at 550 ⁰C, the same working temperature of H13 steel in aluminum extrusion dies. Throughout the test, the mass gain of the untreated substrate, used for comparison, was considered 100, while the borided samples, had mass gain of 83 for the sample borided at 900 ⁰C for 2 hours and 43 for the sample borided at 1000 ⁰C for 4 hours. The oxidation coefficients of the borided samples were similar, indicating similar kinetics of oxidation but different from that of the untreated substrate.