Haharin V. Improvement of technological systems designed for plasma gradient hardening of large steel products

The research aims at further development of the plasma surface hardening technology, namely by creating a gradient structured layer with improved perfor-mance properties on the product surface. In this paper, the mathematical model of stress calculation in a hardened layer with gradient structure has been developed using the finite element method. The calculations of the optimal structure of the gradient plasma hardened surface have been performed in order to get the most favorable equivalent stresses within the surface layer. The effect of plasma gradient hardening geometry on wear resistance of carbon steels has been studied. The samples with different distances between har-dened areas and different angles between the hardening and wearing directions have been tested for wear resistance. A technological system of plasma gradient hardening has been created that allows to define processing modes and geometry of hardened areas application in order to obtain the desired surface characteristics on products made from carbon and alloy steels.