Ultrasonic impact treatment and corrosion test after the austenite phase transformation of SKD11 using a plasma diode electron beam

This study was undertaken for improving the corrosion resistance, hardness, and toughness of SKD11, using the developed plasma diode electron beam equipment (PD-Ebeam). The SKD11 in this study is 1.5 w.t.% high-carbon steel; however, X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) analysis results after the PD-Ebeam treatment reveal that almost the entire iron matrix underwent an austenite phase transformation (F.C.C. crystal structure). Thus, an attempt is made to improve the hardness, toughness, and corrosion resistance using a characteristic of the austenite steel. A hardness enhancement of up to 680 (H.V.) could be achieved through PD-Ebeam heat and ultrasonic impact treatments. Further, the gamma structure sustainability and non-carbide formation were confirmed through the XRD and TEM analysis results. In addition, the friction coefficient in a wear test, was found to be lesser than that of vacuum heat-treated material, owing to the ductility of the gamma phase. As a result, it achieved 18% friction reduction, 47% reduction of wear, and corrosion resistance of level of the stainless steel (SUS304) compared to general vacuum heat treatment.