INVESTIGATION OF CUTTING EDGE RADIUS OF HARDENED FLAT KNIVES AFTER PRODUCTION TESTS

Abstract

One of the important characteristics of flat knives is the radius of rounding of the cutting edge. The smaller the radius of rounding, the more efficient the cutting process is. With the help of various hardening methods, it is possible to reduce the wear of flat knives, so that the radius of rounding of the cutting edge will remain small for longer, and the knife will mow grass crops more efficiently. The most promising methods of knife hardening are HDPE boring, HDPE surfacing FeSi, as well as a combined method including HDPE boring and electric spark treatment. (Research purpose) The research purpose is studying the changes in the radius of the cutting edge of flat knives depending on the hardening technology and the time of their operation. (Materials and methods) Knives made of 65G steel with a length of 125 and 150 millimeters, hardened by HDPE boration, HDPE surfacing by FeSi, a combined method consisting of HDPE boration and electric spark treatment, as well as hardened by HDPE quenching at the manufacturer, were studied. The radii of rounding of the cutting edge of flat knives were measured according to the developed technique, consisting in the production of knife casts made of silicone, viewing the resulting casts on a microscope and calculating the radius using special software. (Results and discussion) It was shown that all three technologies contribute to reducing the dynamics of changes in the radii of rounding of the cutting edges. It was revealed that the best hardening technology was combined processing, and the worst was HDPE surfacing FeSi. (Conclusions) The radii of rounding of the cutting edges were measured. Histograms of the average radii of hardened knives were constructed depending on the hardening technology and the beveled area. It was determined that the hardening of the knives reduces the dynamics of changes in the radii of the rounding of the cutting edges.