RU2377315C1 - Deoxidation method of metal for cold forging - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention relates to ferrous metallurgy, particularly to deoxidation of steel for cold forming. Method includes introduction by metal discharge stroke into casting ladle of solid slag-forming steels, briquetted aluminium, ferromanganese, and at finish aggregate of steel introduction of aluminium rod. By metal discharge stroke into casting ladle and at finish aggregate of steel in the capacity of deoxidising agent it is additionally introduced silicomanganese, additionally, at filling of ladle for 1/5-1/4 part it is introduced 1.2-1.3 kg/t of silicomanganese; 0.4-0.5 of briquetted aluminium and 0.5-0.6 kg/t of ferromanganese, at filling of ladle for 1/3-1/2 part it is introduced 0.5-1.0 kg/t of silicomanganese and 0.8-0.9 kg/t of ferromanganese, at filling of ladle for 1/2-2/3 part solid slag-forming steels are introduced, and by receiving of metal to finish aggregate of steel there is introduced 0.4-0.5 kg/t of silicomanganese and 1.3-1.4 kg/t of aluminium rod.

EFFECT: reduction of consumption of aluminium and reduction of metal screening by defect " blister ".

1 ex

Description

The invention relates to ferrous metallurgy, in particular to the deoxidation of steel for cold stamping.

A known method for the production of silicon-stabilized low-carbon boiling steel, including the release of non-deoxidized metal from the converter, a sequential additive in the steel pouring ladle during the smelting of lime, ferromanganese, aluminum and a second portion of lime, purging with neutral gas, and at the first redistribution, the metal is additionally deoxidized with silicomanganese in an amount of 3 , 5-3.8 kg / t of steel, sitting it with the first portion of lime in a ratio of 1: (0.4-0.8), while in the period between the additives of silicomanganese and ferromanganese 0.5 to 0.6 mass of all metal is poured into the ladle (Patent No. 1790612).

The disadvantage of the described method is the increased sorting of the metal during its subsequent rolling according to the defect of “captivity”, since steel does not always meet the mechanical requirements of GOST.

The closest analog of the claimed invention is a method for the deoxidation of the metal for cold forming, comprising a ladle during filling to _^1/6 - _^1/5 solid parts administering slag mixtures (TSHS) and briquetted aluminum in an amount of 0.6 kg / t, when filling the ladle at _^1/4 - _^1/3 parts ferromanganese administering in an amount of 4.2 kg / t and briquetted aluminum in an amount of 0.8 kg / t and of metal coming in steel refining unit (ADS) - introduction of 0.6 kg / t aluminum wire rods (TI-101-ST-KKC-2-2006, p. 25-26 and TI-101-ST-KKC-22-2005, p. 12-13).

The disadvantage of this method is the high consumption of aluminum, the presence of aluminates in steel, which during subsequent rolling leads to metal sorting according to the “captivity” defect.

The technical problem solved by the invention is to reduce the consumption of aluminum and reduce the sorting of metal according to the defect of the "captivity".

The technical problem is solved in that the method of deoxidation of metal for cold stamping, including the introduction of metal in the steel pouring ladle TShS, briquetted aluminum, ferromanganese and on the finishing unit began the introduction of aluminum wire rod, in contrast to the closest analogue, in the course of metal production in the steel pouring ladle and DT is further added silicomanganese, wherein when filling the ladle _^1/5 - _^1/4 parts administered 1.2-1.3 kg / ton silicomanganese, 0.4-0.5 and 0.5-0.6 aluminum briquetted kg / t ferromanganese, when filling the bucket _^1/3 - _^1/2 pieces are administered 0.5-1.0 kg / ton silicomanganese, 0.8-0.9 kg / t ferromanganese, when filling the ladle _^1/3 - _^2/3 parts TSHS administered, and 0.4–0.5 kg / t of silicomanganese and 1.3–1.4 kg / t of aluminum wire rod are introduced at the ADF.

Introduction first reductants portion of the ladle when filled with less than _^1/5 of the leads to the rapid combustion of the reductants and reduction of their assimilation into the metal and when administered rakisliteley when filling the ladle over _^1/4 part may cause that not all deoxidants have time to dissolve, slag may enter. If the first portion of silicomanganese, briquetted aluminum and ferromanganese are introduced less than the indicated lower limit values, the metal oxidation will not be sufficiently removed, and if these elements are introduced more than the indicated upper limit values, these elements will be overused if the effect is not achieved.

Conducting a second portion of reductants in the casting ladle when filled with at least ^{_one third} part also leads to their rapid combustion and a reduction in the assimilation of the metal, and the introduction of reductants when filling the ladle over _^half portion causes that deoxidizing do not have time to dissolve. If the second portion of silicomanganese and ferromanganese is introduced less than their lower specified limit values, the metal oxidation is not sufficiently reduced, and the introduction of these elements more than the indicated upper limit values does not give the expected effect, but only leads to their overuse.

Introduction TSHS a casting ladle during filling it in less than ¹ / part ₂ has little effect of desulfurization, and administering TSHS when filling the ladle over _^2/3 part results in the fact that lime is not time to dissolve and will not be imposed zhidkopodvizhny slag.

The introduction of deoxidizing agents - silicomanganese and aluminum wire rod on the ADF is less than the specified lower limit values, will lead to insufficient removal of metal oxidation, the specified oxygen content will not be achieved, which will lead to an increased consumption of aluminum wire rod, and the introduction of these deoxidants is greater than the specified upper limit values , will lead to an increased silicon content and the receipt of a non-product.

When conducting experimental swimming trunks with successively exceeding the upper and lower values of the indicated parameters, it was found that the best performance was achieved with the declared parameters.

Concrete example

The proposed method was carried out during the deoxidation of steel grade 08Y at the Magnitogorsk Iron and Steel Works in a 350-ton converter.

109 tons of scrap were loaded into the converter and 295 tons of cast iron were poured. At the end of the purge, the steel temperature was 1654 ° C.

Chemical analysis of steel before release:

C - 0.04%, Mn - 0.05%, S - 0.025%, P - 0.008%.

When filling the _{^ladle-by-1/5} of was given 1,286 kg / m silicomanganese, 0.429 kg / m brikitirovannogo aluminum and 0.572 kg / t ferromanganese, when the level of metal in the ladle _^third part was given a second portion of reductants in an amount of 0.852 kg / t of silicomanganese and 0.858 kg / t of ferromanganese. Further, when filling the ladle _^2/3 TSHS part weighed was given in an amount of CaO - 5.7 kg / ton, CaF ₂ - 1.4 kg / t aluminum brikitirovanny - 1.57 kg / t.

The total consumption of materials and ferroalloys in the bucket amounted to:

FMn - 1,429 kg / t

CMn - 2.143 kg / t

Al bric. - 1.0 kg / t

CaO - 5.7 kg / t

CaF ₂ - 1.4 kg / t.

The chemical composition of the steel before processing on the ADS:

C - 0.05%, Si - 0.015%, Mn - 0.263%, S - 0.0208%, P - 0.009%.

Upon receipt of the metal at the ADF, silicomanganese - 0.429 kg / t and aluminum wire rod - 1.355 kg / t were delivered to the ladle.

The chemical composition of the steel after processing at the ADF:

C - 0.05%, Si - 0.014%, Mn - 0.027%, S - 0.018%, P - 0.09%, Al - 0.046%.

Swimming trunks made by the proposed method satisfy the requirements of GOST in all respects. In addition, aluminum consumption is reduced by 0.6 kg / t, sorting by the “captive” defect is reduced.

Claims (1)

A method of deoxidizing metal for cold stamping, including introducing solid slag mixture (TSS), briquetted aluminum, ferromanganese during the metal production into the steel pouring ladle, and introducing an aluminum wire rod at the steel finishing unit, characterized in that during the metal release into the steel pouring ladle and on the unit for finishing the steel as a deoxidizer is additionally introduced silicomanganese, and when filling the bucket on

part is injected 1.2-1.3 kg / t of silicomanganese, 0.4-0.5 kg / t of briquetted aluminum and 0.5-0.6 kg / t of ferromanganese, when filling the bucket on

parts are introduced 0.5-1.0 kg / t of silicomanganese and 0.8-0.9 kg / t of ferromanganese, when filling the bucket on

parts are injected with TShS, and 1.3-1.4 kg / t of aluminum wire rod and an additional 0.4-0.5 kg / t of silicomanganese are introduced at the steel finishing unit.