RESEARCH INTO THE PROCESS OF OBTAINING HIGH-SILICINE FERRO-CARBON ALLOY ФС15л FOR THE MANUFACTURE OF CORROSION-RESISTANT PARTS OF SULFURIC ACID PRODUCTION EQUIPMENT. Mеssage 1

Abstract

The work investigates the technology of obtaining high-silicon iron-carbon alloy of the ФС15л brand, intended for the manufacture of parts of chemical equipment operating in aggressive acidic environments. The choice of an alloy with a silicon content of 13–15% as a material for the production of tanks of rectification columns for drying sulfuric acid is justified due to its high corrosion resistance, ability to passivation and long service life. In the process of research, the preparation of charge materials, smelting and refining of the starting pig iron from sulfur by the method of magnesium treatment in an IST-016 induction furnace were carried out. Based on the refined pig iron, an iron-carbon melt with a silicon content within 13–15% was obtained, samples were taken for chemical and structural analysis, and the metal was poured into sand-clay molds. To prevent the formation of burn-in, non-stick powders based on powdered quartz were used. Shaped castings and plate samples were obtained for further metallographic, mechanical and corrosion studies. The features of the formation of the structure of high-silicon ferrosilicides, the influence of silicon on the corrosion resistance and technological properties of the alloy were considered. It was established that the silicon content at the level of 13–15% ensures the formation of a stable protective layer on the metal surface, which effectively prevents corrosion destruction in a concentrated sulfuric acid environment. It is shown that the use of alloys of the ФС15л type allows to significantly increase the durability and reliability of chemical equipment, reduce the costs of repair and maintenance and increase the service life of technological installations. The results obtained confirm the prospects of using high-silicon iron-carbon alloys for the manufacture of cast parts for sulfuric acid production and other branches of the chemical industry.