Melting process for producing synthetic cast iron by utilizing SiC carburizing siliconizing

Abstract

The invention discloses a melting process for producing synthetic cast iron by utilizing SiC carburizing siliconizing, which produces the synthetic cast iron by taking scrap steel, pig iron and cast iron returns or scrap steel and cast iron returns as the main raw materials in an induction furnace by utilizing SiC as an carburizing siliconizing agent, wherein the addition of SiC is 0.5-3%, and the granularity is 6-20mm; SiC is added to a hearth before melting or is added during the melting process, or the two modes cooperate to be used. The invention utilizes SiC to replace the pig iron and silicon iron carburizing siliconizing to reduce the pig iron and silicon iron so as to reduce the cost, and meanwhile, the tendency of the molten iron chill and the reverse chill of the produced synthetic cast iron is small; the dimensions of graphite pebbles in produced nodular cast iron are small, the sphericity or roundness is high, the content of ferrite is high, and the roughness of the nodular cast iron is improved; the organization of produced grey cast iron is refined, and the mechanical property and the abrasion resistance are obviously improved. The invention can be used for producingvarious trademarks of grey cast iron, nodular cast iron and alloy cast iron.

Description

Technical field: [0001] The invention relates to a smelting process technology for cast iron materials, in particular to a smelting process for producing synthetic cast iron by increasing carbon and silicon with SiC. Background technique: [0002] In recent years, the prices of pig iron and ferrosilicon have risen sharply, which has greatly increased the production cost of cast iron using pig iron as the main raw material in the traditional process, while the price of scrap steel is much lower than that of virgin iron, and the quantity is large, so no or less virgin iron is used , The smelting technology of synthetic cast iron using scrap steel and returned iron, and then adding carbon and silicon came into being. Under the condition of the same carbon equivalent, the tensile strength of this synthetic cast iron is about 30MPa higher than that of ordinary gray cast iron, and the hardness of synthetic cast iron is generally about 10HB lower than that of ordinary gray cast iro...

AI Technical Summary

Problems solved by technology

[0003] At present, it is widely used at home and abroad to use scrap steel and returned iron as raw materials, and use recarburizers and ferrosilicon to increase carbon and silicon to produce synthetic cast iron, but the price of ferrosilicon in the market is relatively high, which makes the smelting cost in a relatively low High level, in today's pursuit of low cost, it has been the industry's efforts to find a material that can replace ferrosilicon and increase carbon and silicon in the production of synthetic cast iron, and the price is relatively cheap, thereby reducing smelting costs. The direction of silicon carbide (SiC) contains about 70% Si, which is equivalent to the silicon content of ferrosilicon for casting, but its price is much lower than that of ferrosilicon, but how to use silicon carbide in the smelting process to become a problem