AISI 302 and AISI 304 samples are sputtered cleaned at 0.6–1.0 Torr by applying high discharge voltage (∼ 700 V) for 30 min. In this process the sample temperature reaches > 150 °C, by bombardment of hydrogen and nitrogen ions over the negatively biased sample surface. Hydrogen gas helps in reducing the surface oxide present over the surface. The specimens are cooled in a similar manner as in the case of N2 nitriding process after the treatment.