Unravelling the Role of Nitrogen in Surface Chemistry and Oxidation Evolution of Deep Cryogenic Treated High-Alloyed Ferrous Alloy

The role of nitrogen, introduced by deep cryogenic treatment (DCT), has been investigated and unraveled in relation to induced surface chemistry changes improved corrosion resistance high-alloyed ferrous alloy AISI M35. assumptions observations the nitrogen were confirmed using a multitude complementary investigation techniques with strong emphasis on ToF-SIMS. DCT samples display modified thickness, composition layering structure products passive film compared conventionally heat-treated sample under same environmental conditions. is correlated presence so-called ghost layer, which higher concentration nitrogen. This layer acts as precursor for formation green rust magnetite formed. specific combination an effective protective barrier against material degradation. dynamics oxide build-up also changed DCT, elucidated detection different metallic ions their distribution over thickness its CHT counterpart. Newly observed successfully overcomes testing conditions more extreme environments such high temperature vibrations, additionally confirms treated alloys.