Influence of preoxidation and annealing treatments on the isothermal oxidation in air at 1173 K of cerium-implanted EN-1.4301 stainless steel

Improvement of the high temperature oxidation behavior of conventional EN-1.4301 (AISI type 304) stainless steel was achieved by implanting cerium ions. Implantation was performed in samples with two different surface treatments: commercial 2B mill finishing and preoxidation in synthetic air. One set of samples was annealed after implantation in order to recover the damage induced in the crystalline structure. Results show that the implantation of Ce greatly improves the oxidation resistance at 1173 K of the EN-1.4301 grade stainless steels and that the annealing treatment after the implantation is beneficial during the subsequent oxidation. Experiments confirm the presence of spinel-type compounds and Cr2O3 and Fe–Cr mixed oxides with high Cr content in the scale, and martensite being the dominating metallic phase. Chromium depletion in the near-surface layers is also described. Results are compared to previously published data on surface modification using La and Ce by pyrolysis of aerosols.