KEY ENGINEERING MATERIALS

Abstract

In this work, some surface properties of ductile cast irons were improved by boronizing thermo-chemical process. Boronizing was performed in a slurry salt bath consisting of borax, boric acid and ferro-silicon at 850degreesC and 950degreesC for 2-8 hours. Three different ductile cast irons were performed to investigate the surface properties and performance of GGG 50, GGG 60 and GGG 80 ductile irons. Structural characterization of boride layer formed on the surface of ductile cast irons were carried out by using optical microscope, SEM-BEI, electron microprobe analysis and XRD analysis. The higher the boronizing temperature, the longer the treatment time and the lower the copper concentration of ductile cast irons, the higher the hardness and the lower the fracture toughness of boride layer became.