Deoxidizing and modifying properties of alkaline earth metals within ferroalumosilicocalcium and ferrosilicobarium alloys

Abstract

Modification of alloys, in particular, by calcium and barium, is one of the promising directions for obtaining alloys with a fine crystalline structure. Complex ferroalloys – ferroalumosilicocalcium and ferrosilicobarium – were developed in the Chemical and Metallurgical Institute after Zh. Abishev. It was shown, that modification of steel by silicon-aluminum complex alloys containing chemically active elements – calcium and barium, should become one of the most effective methods to improve the quality of machine-building metal products.The chemical compositions of the smelted ferroaluminosiliconcalcium and ferrosilicobarium presented. The melting range of the nonmetallic compound formed during the deoxidation of steel by complex alloy containing calcium determined. Results of mechanical tests of the specimens of steel, modified by a complex alloy containing barium considered. A comparison of microstructure of the current production route steel and deoxidized with the complex alloys was carried out.In the course of metallographic studies of experimental steel specimens, a modifying influence on the morphology of nonmetallic inclusions by calcium and barium, supplied in a complex with aluminum and silicon alloys, was established.Metal processing by complex alloys such as ferrosilicoaluminum with calcium (FASC) and ferrosilicobarium (FSAB) indicates the possibility of achieving a higher degree of refining from oxide nonmetallic inclusions and a more even distribution of them in the ingot.The results of the industrial heats also indicated a possibility of improving of quality of casting through the decreasing of hot thermal cracks and gas-shrinkage defects, cleaner grain boundaries, a significant reduction in the number and size of carbide inclusions.