The relationship between microstructure and corrosion behavior of martensitic high nitrogen stainless steel 30Cr15Mo1N at different austenitizing temperatures was investigated by microscopy observation, electrochemical measurement, X-ray photoelectron spectroscopy analysis and immersion testing. The results indicated that finer Cr-rich M₂N dispersed more homogeneously than coarse M₂₃C₆, and the fractions of M₂₃C₆ and M₂N both decreased with increasing austenitizing temperature. The Cr-depleted zone around M₂₃C₆ was wider and its minimum Cr concentration was lower than M₂N. The metastable pits initiated preferentially around coarse M₂₃C₆ which induced severer Cr-depletion, and the pit growth followed the power law. The increasing of austenitizing temperature induced fewer metastable pit initiation sites, more uniform element distribution and higher contents of Cr, Mo and N in the matrix. In addition, the passive film thickened and Cr₂O₃, Cr³⁺ and CrN enriched with increasing austenitizing temperature, which enhanced the stability of the passive film and repassivation ability of pits. Therefore, as austenitizing temperature increased, the metastable and stable pitting potentials increased and pit growth rate decreased, revealing less susceptible metastable pit initiation, larger repassivation tendency and higher corrosion resistance. The determining factor of pitting potentials could be divided into three stages: dissolution of M₂₃C₆ (below 1000 °C), dissolution of M₂N (from 1000 to 1050 °C) and existence of a few undissolved precipitates and non-metallic inclusions (above 1050 °C).

Stainless steels are used extensively in semiconductor manufacturing as chamber, structure component and gas delivery systems. The corrosion in the aggressive gas in the semiconductor manufacturing industry leads to particle release, contaminating wafers and limiting their application. Moisture content can accelerate the corrosion rate of stainless steel. In a high-temperature environment, the corrosion is determined by the synergistic effect of the vapour of the corrosion product and thermal ageing. To eliminate corrosion, lots of efforts have been performed and categorized into three aspects: (1) Material purification using innovating metallurgy techniques, especially vacuum induction melting (VIM) and vacuum arc remelting (VAR). The ultra-pure stainless steel minimizes the inclusion in stainless steel, suppressing the breakdown of the passive film. (2) Smoothing the surface by polishing; the polishing surface shows hydrophobic behaviour and decreases moisture absorption. (3) Applying surface and coating techniques against corrosion, including passivation treatment and electroplating/electroless Ni-based coating. Herein, the techniques mentioned above are reviewed, and the prospect and development of stainless steel in the semiconductor manufacturing industry are forecasted.