Износостойкость низколегированных сталей в абразивной среде

Abstract

The import substitution of agricultural machinery implements is possible with the development of high quality steel and hardening technologies appropriate to the operating conditions of agricultural machinery. Along with high wear resistance in abrasive environment, steel must have high ductility and impact toughness. To investigate wear resistance of the developed low-alloy steels in the abrasive environment and estimate the possibility of their application for manufacturing high-resistance working tools of agricultural machinery the authors developed four batches of steel samples with additives. All samples were subject to heat treatment with heating to 900°C and quenching in water at 20°C. The second group of samples was additionally tempered at a temperature of 280°C for an hour, followed by air cooling. The wear resistance of samples was determined according to GOST 23.208‑79 with the test equipment. The least wear intensity of 0.0581 g/m was recorded for steel 0.43C‑1.60Si‑0.01Mn‑1.1Cr‑0.95Mo‑0.08V‑ 0.05Nb‑0.04Ti subjected to heat treatment with quenching. The high tensile strength of 2170 MPa was obtained through the formation of carbonitrides enriched with Nb. The wear resistance of this steel grade is 1.66 times higher than that of the 65G steel grade. The heat treatment of quenching with tempering yielded the relative wear resistance of the given steel by 10.7% lower, which can be explained by phase transformations reducing the ultimate strength to 2040 MPa, but increasing the plasticity of steel. Studies have shown a wide range of changes in wear resistance depending on the heat treatment mode. This makes it possible to modify the structure of steel in relatively small temperature intervals of quenching and tempering, thereby influencing the properties that provide the greatest wear resistance.