Eliminating detrimental effect of cold working on pitting corrosion resistance in high nitrogen austenitic stainless steels.

The detrimental effect of cold working on pitting corrosion resistance was surprisingly found totally eliminated in high nitrogen stainless steels (HNS) with higher nitrogen content (0.92 wt.%) by electrochemical tests in chloride solution. Inclusions morphology and microstructure of cold-worked HNS were investigated. Then the passive film on HNS was analyzed by secondary ion mass spectroscopy (SIMS). For the first time nitrogen enrichment as a form of short range ordered [CrN] was observed in the chromium oxide layer of passive film on HNS. A possible reaction involving nitrogen enrichment is proposed to elucidate this exceptional behavior of corrosion resistance for HNS. [ABSTRACT FROM AUTHOR]