Method for controlling carbon equivalent of base iron and application of method

Abstract

The invention relates to a method for controlling the carbon equivalent of base iron and an application of the method. According to the method for controlling the carbon equivalent of base iron and the application of the method, the influence of C and Si elements is mainly taken into consideration for calculation of the carbon equivalent and the influence of microelements on the carbon equivalent is ignored; a molten iron treating agent is quantitatively added to enable the Si content change delta Si before and after molten iron treatment to be a constant value, so the theoretical carbon equivalent CE2, namely (CE-delta Si / 3), of the base iron can be calculated according to the theoretical carbon equivalent value CE of the cast iron; the detection value CE1 of the carbon equivalent of the base iron is controlled to be near the theoretical carbon equivalent CE2, so the carbon equivalent of the base iron can be adjusted to an eutectic point quickly and effectively, the qualified rate of the nodulized molten iron is increased, return of nodular iron is avoided, and the production cost is effectively reduced.

Description

technical field [0001] The invention relates to a control method and application of the carbon equivalent of raw molten iron, belonging to the technical field of cast iron alloys. Background technique [0002] The source of iron ore powder used in ironmaking is very complicated, and many trace elements contained in iron ore powder cannot be controlled at all, resulting in variability in the content of trace elements in pig iron. The carbon equivalent is not only related to the content of C and Si, but also related to Mn, S, P and other trace elements. However, these trace elements are genetically affected during the casting process, which makes it impossible to accurately control the carbon equivalent during batching, resulting in large quality fluctuations. Elements that hinder graphitization such as Mn, Cr, V, Mo, Cr, etc. will reduce the carbon equivalent, and elements that promote graphitization such as S, P, Al, Cu, Ni, etc. will increase the carbon equivalent. The inf...

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Problems solved by technology

The detection of the carbon content of molten iron after spheroidizing by different methods fluctuates greatly, and the calculation of the carbon equivalent of nodular iron is difficult to determine

[0008] Due to the large fluctuations in the detection of the carbon content of molten iron after spheroidizing, it is difficult to determine the carbon equivalent

For a long time in the production of ductile iron at home and abroad, the carbon equivalent control is only based on the value of the molten iron after spheroidization analyzed by the spectrometer, and the experience before the furnace is used to make an approximate judgment on the carbon equivalent. However, in actual production, this method requires iron Whether the molten iron is qualified can only be confirmed and judged after the water is spheroidized. The control method of the carbon equivalent of the molten iron is seriously lagging behind, resulting in large fluctuations in the casting shrinkage and waste rate, sometimes as high as 30%. Unqualified nodular iron needs to be returned to the furnace, which directly leads to production. Cost increases, so this carbon equivalent control method is lagging and unscientific

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