CN1439727A

CN1439727A - Al-Ca-Mg-Fe alloy for final deoxidisation of molten steel and its preparation

Info

Publication number: CN1439727A
Application number: CN 03111224
Authority: CN
Inventors: 郭庆成
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-03-24
Filing date: 2003-03-24
Publication date: 2003-09-03

Abstract

An AlGaMgFe alloy for final deoxidization of molten steel contains Al (30-60%), Ca (2-15%), Mg (2-15%), Si (0-3%) and Fe (rest) and is prepared through proportionally mixing silica rock, lime, coke and iron filings, smelting to obtain low-Si ferrocalcium, adding Al, Mg and Fe, and smelting. It can improve the mechanical performance of steel and prevent the sprute from being blocked, and has desulfurizing effect.

Description

The aluminium Ca, Mg and Fe Alloy And Preparation Method that is used for final deoxygenation of molten steel

One, technical field

The present invention relates to iron alloy, particularly a kind of composite deoxidant aluminium Ca, Mg and Fe Alloy And Preparation Method that is used for final deoxygenation of molten steel.

Two, background technology

The complex deoxidizer for steelmaking of Chu Xianing generally all contained the composition of silicon in recent years, as ferrosilicoaluminum, and Si-Al-Ba-Fe, sial barium strontium iron etc.Though this type of siliceous reductor has deoxidation effect preferably, is used for the steel grade of smelting requirements good toughness, as automobile pressing sheet material steel, when the composition that contains silicon in the steel is higher, the toughness of steel is reduced, cause steel plate that crackle easily takes place in punching course.For this reason, the reductor that is used to smelt the demanding steel grade of unit elongation should reduce the wherein content of silicon as far as possible.

At present, not siliceous reductor, modal is ferroaluminium.Carry out final deoxygenation of molten steel with ferroaluminium,, also have some shortcomings though can obtain deoxidation degree more completely: the one, the deoxidation products Al in the steel ₂O ₃Be mingled with and be bar shaped,, cause that the mechanical property of steel is had considerable influence because of its plasticity-not; The 2nd, Al ₂O ₃The fusing point height easily condenses into knurl when pouring molten steel, stop up the mouth of a river, and is particularly unfavorable to continuous casting; The 3rd, itself does not have sweetening effectiveness alloy, can not satisfy the steel grade of some needs deoxidation simultaneously and desulfurization; The 4th, this alloy is easily efflorescence in air, and inconvenience stores.

Three, summary of the invention

The purpose of this invention is to provide a kind of final deoxygenation of molten steel agent aluminium Ca, Mg and Fe alloy that is used for, with this alloy deoxidation, can improve the steel inclusion form, improve the steel comprehensive mechanical performance, nozzle clogging stops up in the time of avoiding pouring molten steel, in deoxidation, have sweetening effectiveness concurrently, and in air, be difficult for efflorescence.The present invention also provides the preparation method of this alloy.

Aluminium Ca, Mg and Fe alloy provided by the invention, its chemical ingredients (weight ratio) is: Al 30-60%, Ca 2-15%, Mg 2-15%, Si≤3%, surplus is Fe.

The preparation method of aluminium Ca, Mg and Fe alloy provided by the invention, the one, directly being lower than 16% calcium iron with metallic aluminium and MAGNESIUM METAL and silicone content is raw material, forms with the main frequency furnace melting once.The 2nd, smelt in two steps with hot stove in ore deposit and main frequency furnace, be that the first step is earlier by silica 30-50Kg, lime 120-170Kg, coke 25-40Kg, iron filings 50-70Kg ratio of components batching will be prepared burden and be carried out reducing and smelting with the hot stove in ore deposit in batches, make chemical ingredients (weight ratio) and be Si 14-18%, Ca 30-35%, surplus is the low silico-calcium iron of Fe; In second step, the low silico-calcium iron that makes with metallic aluminium, MAGNESIUM METAL, iron and the first step is prepared burden by the proportioning raw materials that the chemical ingredients of said aluminium Ca, Mg and Fe alloy calculates, and is smelted into the aluminium Ca, Mg and Fe alloy of said chemical ingredients with main frequency furnace with preparing burden in batches.

Aluminium Ca, Mg and Fe alloy provided by the invention because calcium can make steel inclusion nodularization sex change, thereby is improved the comprehensive mechanical performance of steel.Calcium also can make deoxidation products form more low-melting calcium-aluminate, and come-up is removed easily in molten steel, nozzle clogging latch up phenomenon in the time of therefore can avoiding pouring molten steel.Magnesium in the alloy is good sweetening agent, adds that calcium and sulphur also have good avidity, and therefore, this alloy has sweetening effectiveness preferably concurrently in deoxidation.After adding calcium and magnesium, hardness of alloy can improve, and is difficult for efflorescence in air, and the storage time prolongs.

The content of calcium and magnesium is unsuitable too high and low excessively in the aluminium Ca, Mg and Fe alloy of the present invention, and content is lower than 2%, its DeGrain; Surpass 15%, meaning is also little, and higher because of the vapour pressure of calcium and magnesium, too much calcium and magnesium are met the molten steel scaling loss that easily gasifies, and do not have effect.

Four, embodiment

Embodiment

Prepare aluminium Ca, Mg and Fe alloy of the present invention according to the following steps:

(1) press silica 40Kg, lime 135Kg, coke 35Kg, iron filings 60Kg batching becomes chemical ingredients (weight ratio) to be Si 16% with the 2500KVA mine heat furnace smelting, and Ca 33%, and surplus is the low silico-calcium iron of Fe;

(2) the low silico-calcium iron 50Kg that makes by above-mentioned steps, metallic aluminium 200Kg, MAGNESIUM METAL 20Kg, iron 130Kg batching is used the main frequency furnace fusion, and making weight ratio is Al 50%, and Ca 4%, and Mg 5%, and Si 2%, and surplus is the aluminium Ca, Mg and Fe alloy of Fe.

This aluminium Ca, Mg and Fe alloy is used to smelt 08 Al steel final deoxygenations, oxygen content in steel after the deoxidation can reach below the 30ppm, and sulphur content reduces 30-40%, below the steel inclusion total amount 60ppm, the comprehensive mechanical performance of steel, especially unit elongation obviously improve with siliceous reductor.Mouth of a river non-nodulating is not stopped up when pouring molten steel and continuous casting.In air, deposit a not efflorescence in month.

Claims

1, a kind of aluminium Ca, Mg and Fe alloy that is used for final deoxygenation of molten steel is characterized in that the chemical ingredients of this alloy (weight ratio) is: Al 30-60%, and Ca 2-15%, Mg 2-15%, Si≤3%, surplus is Fe.

2, as the preparation method of the said aluminium Ca, Mg and Fe of claim 1 alloy, it is characterized in that, may further comprise the steps:

The first step is pressed silica 30-50Kg, lime 120-170Kg, coke 25-40Kg, iron filings 50-70Kg ratio of components batching will be prepared burden and be carried out reducing and smelting with the hot stove in ore deposit in batches, make chemical ingredients (weight ratio) and be Si 14-18%, Ca 30-35%, surplus is the low silico-calcium iron of Fe;

Second step, the low aluminium calcium iron that makes with metallic aluminium, MAGNESIUM METAL, iron and the first step is raw material, prepare burden by the proportioning raw materials that the chemical ingredients of said aluminium Ca, Mg and Fe alloy calculates, batching is smelted into the aluminium Ca, Mg and Fe alloy of required chemical ingredients in batches with main frequency furnace.