Elaboration of a methodology of quality complex estimation of hot-stamped elliptical bottoms

Last years products quality is estimated often by complex indices by application quality control principles. Usage of them enables to estimate and compare product quality for different variants of technology processes by a unified scale more objectively. The authors presented an approach to estimation of products quality by application of complex indices relating to hotstamped elliptical bottoms. Results of analysis of GOST requirements for the products quoted, the analysis being aimed at determining of single indices. 17 single properties of the products chosen and normalized. With the purpose of single properties estimation by a unified scale, formulas proposed for quality indices normalizing in the interval (0...1) relating to dispersion of properties values allowed by GOST. At the final stage the quality estimation of selected bottoms was made by the complex index of the product quality, calculated by two variants: as an arithmetic average weighted and geometric average weighted of 17 values of single properties. The calculated complex indices estimated by the Harrington desirability scale. Definite indices values turned out to exceed 0.8, which corresponds to high quality, even exceeding to some extent the standards requirements. It was shown, that arithmetic average weighted and geometric average weighted values of complex indices have close values and in the whole this product has a high quality. The elaborated methodology enabled to estimate the quality of hot-stamped elliptical bottoms produced by JSC “Uralchimmash” and reveal reserves of its increase at the expense of improving technological regimes of bottoms treatment at all the stages.