COMPARATIVE STUDY OF CORROSION BEHAVIOR FOR PLASMA NITRIDED 1045 CARBON STEEL WITH AND WITHOUT PRETREATMENT OF SAND BLASTING

Abstract

A pretreatment of sand blasting with the duration of 15[Formula: see text]min was carried out prior to plasma nitriding for 1045 carbon steel in this study. The corrosion behavior was evaluated by means of electrochemical polarization, electrochemical impedance spectroscopy (EIS) and soaking test, and compared with that without pretreatment of sand blasting. The results show that the pretreatment of sand blasting can significantly enhance the corrosion resistance, the corrosion potential shift to the noble direction, with higher corrosion potential of [Formula: see text][Formula: see text]mV and lower corrosion current of 0.0853[Formula: see text][Formula: see text]A/cm2, and exhibit larger diameter, higher phase angle and wider frequency region, there exists no corrosion pit after soaking test, and the corrosion rate is decreased from 0.0387[Formula: see text]g/mm2 to 0.01341[Formula: see text]g/mm2, only 1/3 comparing with that of sample without pretreatment of sand blasting. The enhancement mechanism of corrosion behavior is mainly ascribed to the excellent protection from the thicker and denser compound layer with higher amount of [Formula: see text]-Fe[Formula: see text]N.