ENHANCEMENT OF BENDING STRENGTH OF HEAT-RESISTANT STEEL BY ION CARBONITRIDING

The heat-resistant steel 20Kh3MVF-Sh is used for toothed gears employe d in pumps of turbojet engines. In service, the working surface of the gears is subjected To intensive wear. Using gas-phase carburizing to case-harden such gears has proven to be insufficiently effective. In t his work we have investigated the structure, the chemical composition, and the wear resistance of 20Kh3MVF-Sh steel after ion carbonitriding . We have obtained regression equations relating the wear resistance c haracteristics to the carbon and nitrogen concentration and the hardne ss of the diffusion layer. We have developed a combination process for ion carbonitriding which increases the wear resistance or steel 20Kh3 MVF-Sh.