Effect of siliconizing with molten salt on the wear resistance and corrosion resistance of AISI 302 stainless steel

An alloyed Fe-Si intermetallic compound layer was prepared on the surface of 302 stainless steel via a nonelectrolytic molten salt silicon infiltration method at different holding times (2 h and 4 h). The wear resistances of the substrate and siliconized layers were evaluated through microhardness, toughness, friction and wear testing. The corrosion behavior and electrochemical corrosion performance of the substrate and siliconized layers in H2SO4 were evaluated through static immersion and electrochemical testing, and the main factors affecting the corrosion behavior were analyzed. The results showed that the 2-h and 4-h siliconized layers exhibited better wear resistance and pitting resistance than the 302 substrates; these enhancements were mainly due to the alloyed Fe-Si intermetallic compound formed on the surface of the siliconized layer. However, the 2-h and 4-h siliconized layers exhibited different wear resistance and corrosion resistance. The wear volume of the 2-h siliconized layer was 82.5% less than that of the base material and approximately 40% that of the 4-h siliconized layer. The 4-h silicon-infiltrated layer exhibited excellent pitting resistance and passivation characteristics in 10 wt% H2SO4, and the self-corrosion current density of this layer was orders of magnitude less than that of the 2-h silicon-infiltrated layer