FEATURES OF THE FORMATION OF THE PHASE COMPOSITION AND PROPERTIES OF HIGH ALLOY STEEL 03Х17Н3Г9МБДЮЧ

Purpose. Evaluation of the influence of alloying elements of corrosion-resistant steel 03Х17Н3Г9МБДЮч on the phase composition and indicators of high-temperature corrosion. Research methods. In order to check the effect of the chemical composition on the structure of steel 03Х17Н3Г9МБДЮч, laboratory steels were made. The production of these steels was carried out in an induction furnace with a main lining with a capacity of 50 kg. The resulting castings were forged into blanks 40 ´ 80 ´100 mm in size, with subsequent hot rolling into samples 25, 20, and 15 mm thick. Determination of the yield strength of steels was carried out after exposure at a temperature of 850 °С for 10,000 hours. The corrosion resistance of the test samples was determined by the gravimetric method after the samples were completely immersed in molten magnesium. Results. The choice of the main alloying elements was justified and their influence on durability in the aggressive environment of the recovery process of spongy titanium production was determined. A thermodynamic calculation of the changed Gibbs energy in the operating temperature range was performed. The required phase ratio of 03Х17Н3Г9МБДЮч steel was considered and selected based on Scheffler de Long and Potak-Sahalevich diagrams. Scientific novelty. The effect of changing the chemical composition of steel 03Х17Н3Г9МБДЮч within technical conditions on the creep limit and durability in the aggressive environment of the recovery process of the production of spongy titanium was determined. Practical value. It is shown that the alloying complex of corrosion-resistant steel is capable of significantly improving the physical, mechanical and technological properties, and expanding the functional application (purpose).