Development of crusher blade for PET plastic recycling machine using a hard-facing welding technique

Abstract

This study aimed to improve the wear resistance of plastic crusher blades through hard-facing welding, compared to the outcomes with the traditional SKD11 crusher blade. Hard-facing layers were applied to the JIS S45C base material using a chromium carbide electrode (MG710W). Visual inspection was used to assess the welding quality, and a thorough microstructure examination was conducted using SEM-EDS and XRD for structural properties, elemental compositions, and phases. The surface properties hardness and abrasive wear were tested to evaluate wear resistance. The hardness test results showed comparable values between the welded specimen and SKD11. SEM and XRD analyses revealed a structure consisting of martensite, Cr23C6, and Cr7C3 carbides. Wear tests indicated higher weight loss in the welded specimens, attributed to low amounts of chromium carbide in the welded microstructure. Performance tests after plastic chopping showed similar wear on the cutting edge of the welded specimen and SKD11. Cost estimations showed a 45% lower production cost for welded specimens, attributed to the use of inexpensive JISS45C base metal. Despite the additional hard-facing welding step, the overall production cost remained more economical than using SKD11.