A scrap steel smelting ductile iron process with a recarburizer absorption rate of over 95%

Abstract

The invention discloses a waste-steel-smelting-ductile-iron process with the carburant absorptivity reaching 95% or above. In a smelting furnace, furnace burdens and carburant are added at many times, and the furnace burdens comprise ductile iron chippings, foundry returns and waste steel; after the furnace burdens in the smelting furnace completely fuse, temperature rise is started, after all carburant fuses completely, a slag remover is added, and slag is picked out of the furnace with a rolling rod; after stokehole samples are tested to be qualified, spheroidizing is started, and then secondary inoculation is carried out; casting is carried out; the nodulizing stage of obtained ductile iron is 2 stage to 3 stage, and the hardness ranges from 155 HB to 165 HB; and based on the mass percent of the ductile iron, the pearlite content is 5%+ / -0.5%, the S content is smaller than 0.02%, the ferrite content is larger than 85%, and free cementite is not contained. According to the process, through creative detail treatment and furnace burden mastering in the production process, the carburant absorptivity is remarkably improved, the product quality is improved, and the production cost is reduced.

Description

technical field [0001] The invention belongs to the field of metal materials and relates to a scrap steel smelting ductile iron process, in particular to a scrap steel smelting ductile iron process with a recarburizer absorption rate of over 95%. Background technique [0002] Ductile iron (referred to as nodular iron) is spherical graphite obtained through spheroidization and other treatments, which effectively improves the mechanical properties of cast iron, especially improves plasticity and toughness, thereby obtaining higher strength than carbon steel. Ductile cast iron is a recently developed high-strength cast iron material. Its comprehensive properties are close to steel. Ductile cast iron has excellent high-temperature strength and oxidation resistance. It is based on its excellent performance that ductile cast iron has rapidly developed to be second only to gray cast iron. Cast iron is a cast iron material that is widely used. [0003] The production of ductile iro...

AI Technical Summary

Problems solved by technology

[0012] 2. The influence of the amount of carburant added;

[0020] However, due to reasons such as product cost and technology, the absorption rate of the carburizer needs to be above 95%, and on the basis of the existing technology combined with the above five major influencing factors, the absorption rate of the carburant can reach more than 95% for scrap steel smelting ductile iron The process is not satisfactory, or it is difficult to stabilize, or the process is complicated, or the cost is high

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