SU692680A1 - Method of casting metal-rolling rolls - Google Patents

Description

(54) METHOD FOR CASTING ROLL ROLLS

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The invention relates to a foundry, and in particular to the cast iron rolling rolls.

There is a method of casting iron casting rolls, including the processing of cast iron with magnesium or its low-percentage alloys (ligatures) 1,

Treating pig iron with magnesium. The tendency of the pig iron to overcool during solidification increases the content of structurally free cementite and makes it difficult to regulate the hardness and other high-quality x-characteristics of the rolls.

Graphitizing modifiers, such as 75% ferrosilicon 2, are introduced to increase the hardness of the topstocks, as well as to increase the dispersion of the structure when the rolls are poured into a jet of metal treated with magnesium or ligatures in a ladle.

In this way rolls are cast from cast irons with various doping ..

When casting titanium-copper iron rolls, the de-bulking effect of titanium and copper is enhanced by the graphitizing modification. The shape of graphite deteriorates, the transition from spherical to plate, which causes a decrease in quality, cast rolls. This process contributes to a relatively large. the period of time from the treatment of cast iron with magnesium to casting, as well as the considerable mass of castings and the slow cooling of the roll, especially the drive parts hardening in sand-clay forms.

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The purpose of the invention is to improve the shape of graphite and improve the quality of the rolls of titanium copper iron.

This is achieved by the fact that together with the graphitizing modifiers in

When the metal is poured, magnesium is additionally introduced in the form of a crushed ligature with a flow rate of 0.0050, 010 kg of magnesium per ton of liquid metal, for every 0.01% content of titanium and 0.1% of copper in cast iron.

Such a late addition of magnesium with the indicated consumption completely neutralizes the de-bulking effect of titanium and copper and

Claims (2)

5 conditions for casting rolls provides spherical graphite. The foregoing magnesium flow rates are a prerequisite for applying the developed method. If the magnet consumption is less than 0.005 kg. :. . b -. for every 0.01% of TiTf § and 0.1% of copper in - the preparation of spherical graphite in cast iron will not be provided. The consumption of mag no more than 0,010 kg for every 0.01% of titanium content and 0, 1% of the copper content in the pig iron leads to the formation of specific defects, GK and black spots in the cast iron. Example, Cast iron containing 3.06% carbon, 1.26% silicon, 0.49% manganese, 0/186% Phosphorus, O, 03% sulfur, 0.7% nickel. About 37% of chromium, 0.4% of copper and 0.04% of titanium are melted in a fiery furnace, after which they are released into the reining ladle. The treatment of the cast iron with magnesium is carried out in a casting ladle in accordance with known recommendations. The consumption of magnesium per treatment (in kg per ton of iron) is 1.66 plus 0.03-0.05 for every 0.01% of the sulfur content in the iron. When FILLED, a graphicalizing modifier, ferrosilicon-FS-75, is introduced into the metal stream at a rate of 1 kg per ton of liquid metal. In addition, crushed ligature of magnesium (LC-1 magnetism of ligature) was introduced into the metal stream during pouring at a rate of 0.008 kg of magnesium per 0.01% of titanium and 0.1% copper from copper, the total magnesium consumption was 0.064 kg per ton of liquid iron. With an average content of magnesium in the ligature of 5% consumption. . "..,: /." "V 1 and ha tours amount to 1.3 kg and a ton of liquid iron. in the cast iron structure, graphite is spherical in shape, the hardness of the rolls meets the requirements. Formula of the invention. the fact that, in order to improve the shape of graphite and improve the quality of the rolls of titanium-copper iron, together with the graphitizing modifiers, magnesium in the form of a crushed master alloy with: a flow rate of 0.005-0.010 kg of magnesium per ton of liquid metal for every 0.01% of titanium content and 0.1% of copper content; in cast iron. Sources of information taken into account in the examination 1. Krivosheev AE Cast rolls, M., Metallurgists 1957, p. 260 .. 2. Pisarenko G.A. Filippov A.S. Castings of metallurgical equipment from nodular cast iron, M., metallurgists, 1960, p. 85 (prototype),.