Study on Low-Damage Cutting of Alfalfa Stalks by Self-Sharpening Blades of Gradient Material with Carbon-Nitron-Boronized Heat-Treatment

Abstract

The work aims to realize low-damage cutting of Alfalfa stalk. The self-sharpening blades of gradient material were prepared by 40 Cr steel, then heat-treating the flank surface by carbon-nitron-boronized with a rare elements catalysis technique. The biological characteristics of Alfalfa incision self-healing and regeneration process were analyzed in order to compare the cutting effects of different blades. After treatment with carbon-nitron-boronized with rare elements catalysis, the flank surface and tip point of blades were coated by boride layer and carbonitriding layer. The composition, microstructure and properties of the carbon-nitron-boronized layer demonstrated a gradient distribution state, and had good wear resistance. A kinetic model for the formation of the carbon-nitron-boronized layer was proposed. The initial stage of heat-treatment was mainly a carbonitriding process. When continuous and compact boride was formed on the surface, it was mainly boridized. The results of field experiment indicated that compared with the commercial blades, the self-sharpening blades have excellent properties as wear resistance and long service life. In addition, the cut damage caused by the self-sharpening blades was less, the self-healing and regeneration process of Alfalfa stalk was normal, and the regeneration duration was greatly shortened. The blades with carbon-nitron-boronized heat-treatment could form the self-sharpening characteristics, always maintaining the cutting sharpness, and realized the low-damage cutting of Alfalfa stalk.