Statistical modelling of cathodic and plasma nitriding of stainless steel
In work the questions connected with mathematical modeling of difficult (multiple-factor) technological processes to which, in particular, it is possible to refer also the chemical heat treatment (CHT) of metals in the category are considered. Chemical heat treatment in the category is the perspective direction of superficial hardening of metals both from the point of view of environmental friendliness of process, and from the point of view of productivity and quality of the received diffusive layers. The Ion-plasma Nitriding (IPN) - a method of chemical heat treatment of products from steel and cast iron with great technological capabilities, is developed as abroad for a long time, and in Russia. The best indicators are shown by rather new version IPN - the cathodic and plasma nitriding (CPN) to which mathematical modeling this work is devoted. Considering that the majority of details of cars and mechanisms are affected in use by hostile environment, to friction and high contact loadings, modeling of CPN of stainless steels is executed. The regression analysis is called the main method of modern mathematical statistics for identification of the implicit and veiled communications between data of supervision. Creation of the equation of regression is carried out, as a rule, by method of the smallest squares which essence consists in minimization of the sum of squares of deviations of the actual values of a resultantly sign from his calculated values. For receiving mathematical models used decomposition of unknown function in a row of Taylor in the vicinity of any point of area of her definition in factorial space. In work the KPA statistical models of stainless steel 08X18H10T allowing to optimize process of HTO at the solution of problems of reduction of time of nitriding, obtaining the maximum thickness of a covering, receiving a covering with the largest hardness (wear resistance) or corrosion resistance are received.