Silicocalcium SiCa60: Production, properties, application

The paper presents the results of research on development of a new alloy for processing steel melt with calcium. The resulting material is an alloy based on the higher calcium silicides CaSi, Ca 5 Si 3 and Ca 2 Si and contains 50 – 75 % Ca. The distinctive properties of such high-percentage silicocalcium are its high melting point and high oxidation resistance. Industrial tests of the new alloy during the treatment of steel melt with calcium before casting at the casting plant showed an almost complete absence of pyroeffect. The degree of calcium absorption was 15 – 20 %, with a calcium content of 0.0015 – 0.0030 % at the continuous casting machine (CCM). The cost of calcium treatment of steel is reduced by 1.5 – 2.0 times compared to traditional materials. The SHS technology of a new high-percentage silicocalcium of the SiCa60 grade was developed, which makes it possible to synthesize an alloy with a strictly specified calcium content using powders and/or granules of calcium and silicon as raw materials with minimal energy consumption. The authors developed the design of cored wire with SiCa60 filler. Composition of the new cored wire is characterized by a maximum content of calcium and a minimum of ballast materials. The use of cored wire with a new filler significantly reduces the consumption of calcium-containing material and reduces the duration of melt treatment.