Tytuł pozycji:
Glow discharge assisted low - temperature nitriding of knives used in wood processing
Purpose: The plasma assisted surface treatment processes may be conducted at lowered temperatures thanks to shallow ion implantation influencing the driving force of diffusion. The low-temperature d.c. glow discharge assisted nitriding (LTN) method allows the process to be applied to steel grades irrespective of their tempering temperature but does not promote the formation of thick nitrided layers. The LTN process seems to be most suitable for improving the mechanical properties of cutting tools. The aim of this study was to elaborate the optimised LTN method of steel cutting tools treatment and its application for production ecological and cheap knives for wood processing industry. Design/methodology/approach: The nitriding of low-alloy steel knives was conducted at temperatures of 320°C-350°C under a pressure of 4hPa. The microstructure and chemical composition of the nitrided layer was determined using XRD and XPS methods and the cutting properties of nitrided knives were investigated in wood processing industry. Findings: The LTN process enables to control very precisely the microhardness distribution profile which decides on the cutting properties of a knife. The optimal process parameters were determined, they depended on the kind of tools application. Practical implications: The LTN treated knives have been used in industry as planar knives and cutting heads for processing wet and dry, hard and soft wood. They appear to be competitive to traditional tools, ecological and cheap. Originality/value: The elaborated low-temperature nitriding of low-alloy steel knives is an original process. The nitrided knives are a new sort of tools for wood processing.