SU1337191A1 - Method of producing cast iron two-layer rolls - Google Patents

Abstract

The invention relates to the production of rolling rolls. The purpose of the invention is to improve the quality of the rolls. The mold is filled with low-silicon iron with simultaneous modification of tellurium with a flow rate determined by the formula P (0.015 ... 0.03) -C-PM, where C is the desired depth of the bleached layer, mm; P - increment of the bleached working layer, mm; M is the mass of the mill roll, t, and after holding to form the working layer, it is washed with gray high-silicon iron. Bleaching growth is achieved due to differentiated modification by tellurium. The method allows to obtain a predetermined depth of the working layer of cast-iron double-layer mill rolls, as a result, the service life of the rolls increases by no less than 5% from 00 s

Description

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The invention relates to a foundry, namely, the production of iron rolling rolls.

The purpose of the invention} w - improving the quality of the rolls.

When casting, low-silicon iron is modified with tellurium in the form during the casting process, and tellurium consumption (in grams), depending on the desired depth of the bleached layer, is 0.015-0.03 times the desired depth of the bleached layer (in mm) by the increment of the bleached layer (in mm) , per mill roll weight (in tons)

Example. Cast iron rolling rolls of the type LPHND 70 with a barrel diameter of 700 mm and a roll weight of 9 tons were cast. The chemical composition of low-silicon iron, weight. % C 2.65; Si 0.45; Mp 0.5; P 0.45; Cr 0.75; Ni 3.7, the rest is iron. Temperature zapivka 340 ° C. After that, a shutter speed was made to form the working roll. Then npotftiiBKy was produced by high-silicon iron with the following chemical composition, wt.%: С 3.55; Si 1,2; Mp 0.45 P 0.25; At 0.05. Cast iron poured at. The specified depth of the working layer of the roll is 30 mm. By test, it is determined that unmodified low-silicon iron gives a chill off with a depth of 12 mm, i.e. It is necessary to get an increment of 18 mm. In this case, the minimum amount of tellurium (in grams), entered directly into the form, is equal to

, 015OOCH8 9 72.9.

The maximum amount of tellurium is:

, 03x3048 9-145,8.

When entering less than 72.9% of tellurium into the mold, the depth of chill is less than the required1X 30 mm. With the introduction of more than 145.8 g of tellurium, detachment of the working roll layer is observed, and a carbide mesh appears in the neck, which is unacceptable.

If the amount entered into the mold when pouring tellurium is less than 0.015 times the required depth of the bleached by the increment of the bleached layer, by the mass of the wafer, then due to the slowing down of the cooling rate over the cross section

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The working layer of the roll and the decrease in the effectiveness of tellurium in time in the bleached layer will be graphite inclusions, and its depth will be insufficient, which reduces the quality of the roll.

If the amount entered into the mold when pouring tellurium is more than 0.03 times the desired depth of bleaching by the increment of the bleached layer and the weight of the roll, then the bleaching effect of tellurium spreads to the transition zone of the casting, which leads to the detachment of the working layer of the roll.

According to the proposed method, the obtained chill increase is achieved due to the differentiated modification of tellurium, the determining criterion of which is not the growth of the chill depth, but the required value of the working roll. Observance of the specified parameters provides obtaining the set depth of the working layer of pig-iron two-layer mill rolls.

The method of casting iron double-sided rolls will improve their quality and quality of rolled metal, reduce

roll consumption by increasing them

service life.

Claims (1)

Invention Formula A method of producing cast-iron double-layer rolling rolls, mainly using tellurium to modify low-silicon iron, comprising filling the mold with bleached low-silicon iron, holding to form the working layer and washing with gray high-silicon iron, in order to improve the quality of the non-current, non-normal, non-woven, and to create a non-woven, high-quality, non-irradiated pig iron, so as to make the style, a simple, non-standard, non-woven, non-woven, and rinse with high-quality, high-ductile iron, in order to improve the quality of the non-standard, non-woven, and to wash with a non-woven, non-woven, high-quality, high-ductile, non-irradiated iron. produced in the process of filling the mold with a flow rate (P), determined by the formula P (0.015 ... 0.6z) -C-P.M, where C is the required depth of the bleached layer, mm; P - increment of the bleached working layer, mm; M is the mass of the mill roll, t.