Microstructure and Properties of Cast Iron Using Chromizing Process

Abstract

Cast iron was chromized by solid powder method at 1000°C. Micro-morphology and microstructure of chromized alloy layer and cast iron matrix were analyzed, their hardness, elements distribution and corrosion resistance were studied in depth. The analysis results revealed that the chromized carbide-chromium layer grew well on cast iron surface, which was smooth and free from macroscopic defect. Campared with the hardness of original cast iron matrix, the hardness of the chromized alloy layer has been improved by 3.5 times, which was as high as 918.8 HV. And the corrosion resistance of the chromized alloy layer has been greatly improved. The relative corrosion rate of the original cast iron matrix was 2.2 times that of the chromized alloy layer according to their polarization curves.