Low-Temperature cementation-perspective technology of hardening of toothed parts

Abstract

© Published under licence by IOP Publishing Ltd. The structure, properties and geometrical accuracy of gear wheels after chemical heat treatment which cementation was carried out at 930°C and 870°C are investigated. Advantage of low-Temperature cementation of toothed parts in size of a radial runout, fluctuation of a side clearance, ovality of an internal opening and the area of a spot of contact between teeths of the strengthened gear wheels is shown. Influence of structure of the endothermic atmosphere on mechanical properties and intensity of saturation by carbon steel 15HGN2TA and 20HGNMTA is investigated. It is established that increase in content of hydrogen from 20% to 40% in the endoatmosphere increases saturation speed carbon steel by 10-34%, excludes their hydrogen saturation and keeps indicators of mechanical properties of the cemented parts. The technology of chemical heat treatment of toothed parts including cementation at 870°C in the endothermic atmosphere containing 40% of hydrogen in the structure is developed and recommended for application.