National University of Science and Technology “MISIS”, Moscow, Russia

Zh. V. Eremeeva, Dr. Eng., Prof., Curator of the Dept. of Powder Metallurgy and Functional Coatings, e-mail: eremeeva-shanna@yandex.ru

Moscow Polytechnic University “Moscow Polytech”, Moscow, Russia
Yu. S. Ter-Vaganyants, Cand. Eng., Associate Prof., e-mail: juliatv1990@mail.ru

This article examines the influence of the lubricant-plasticizer iron stearate and various technological factors on the sintering process of powder alloy steel SP40KhSMF. Such factors of the technological process of powder steel production as molding pressure, temperature and sintering duration were considered. The molding pressure varied from 200 to 800 MPa. Sintering was carried out in two stages. At the first stage, the temperature was 1000 °C, the holding time at this temperature was 60 min. At the second stage of sintering, temperatures varied from 900 to 1200 °C, holding time from 30 to 180 min. Iron stearate was introduced into the powder mixture in an amount of 0.5; 1; 2 and 3 wt. %. The results of a study of the influence of molding pressure on the density of sintered samples showed that the highest density values are achieved at molding pressures of 700-800 MPa. A study of the effect of isothermal holding time on the sintering process showed that the maximum density value of 7.19 g/cm3 is achieved during sintering at the second stage for 180 min. A study of the dependence of density on sintering temperature showed that the highest density values at the second stage of sintering are observed at a sintering temperature of 1200 °C. The introduction of iron stearate into the SP40KhSMF powder steel charge has a positive effect on increasing the density of the samples under study; the highest density values were achieved when 3 wt. % iron stearate.

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