EP0141760B2 - Procédé de traitement de l'acier par le calcium permettant d'obtenir une grande aptitude à la mise en forme à froid et une basse teneur en silicium - Google Patents

Procédé de traitement de l'acier par le calcium permettant d'obtenir une grande aptitude à la mise en forme à froid et une basse teneur en silicium Download PDF

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Publication number
EP0141760B2
EP0141760B2 EP84420156A EP84420156A EP0141760B2 EP 0141760 B2 EP0141760 B2 EP 0141760B2 EP 84420156 A EP84420156 A EP 84420156A EP 84420156 A EP84420156 A EP 84420156A EP 0141760 B2 EP0141760 B2 EP 0141760B2
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EP
European Patent Office
Prior art keywords
calcium
steel
filled wire
divided material
casing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP84420156A
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German (de)
English (en)
French (fr)
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EP0141760A1 (fr
EP0141760B1 (fr
Inventor
André Gueussier
Edmond Vachiery
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Vallourec SA
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Vallourec SA
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Publication date
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Application filed by Vallourec SA filed Critical Vallourec SA
Priority to AT84420156T priority Critical patent/ATE26307T1/de
Publication of EP0141760A1 publication Critical patent/EP0141760A1/fr
Application granted granted Critical
Publication of EP0141760B1 publication Critical patent/EP0141760B1/fr
Publication of EP0141760B2 publication Critical patent/EP0141760B2/fr
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/0056—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00 using cored wires
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/04—Removing impurities by adding a treating agent
    • C21C7/06—Deoxidising, e.g. killing
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
    • C22B9/10—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals with refining or fluxing agents; Use of materials therefor, e.g. slagging or scorifying agents
    • C22B9/103—Methods of introduction of solid or liquid refining or fluxing agents

Definitions

  • the process which is the subject of the invention relates to steels whose inclusions, thanks to an appropriate treatment, remain globular after rolling which which gives the state of employment particularly advantageous properties such as a great ability to stamping or cold stamping.
  • the steels thus treated have improved properties in many fields: isotropy, ductility, machinability.
  • this addition of calcium makes the inclusions present in the liquid metal liquid and therefore avoids the risk of clogging of the continuous casting nozzles.
  • Such steels must have a very low silicon content.
  • the limit not to be exceeded is most often 20 to 30 thousandths percent of silicon.
  • the silico-calcium used contains approximately 30% of Ca, 60% of Si and 10% of Fe + various impurities.
  • the weight of this silico-calcium which must be introduced into the liquid steel to obtain the full effectiveness of the calcium is approximately 0.5 to 1.5 kg per ton of liquid steel.
  • the process for the preparation of a steel having a great aptitude for cold forming according to the invention consists in preparing a liquid steel calmed with aluminum having a silicon content of less than 5 thousandths% by mass and then introducing in this liquid steel a cored wire which contains a divided material.
  • This divided material comprises at least two components: the first of these components is metallic calcium in grains of which the content of particles smaller than the meshes of the sieve of 150 mesh does not exceed 2 to 3% by weight of said component, the second is silico-calcium containing in% by mass Ca 25 to 35, Si 50 to 70, Fe and impurities 5 to 15, the mass ratio K, in the divided material, between the first component and the second being between 0.1 and 3 and preferably between 0.3 and 23, the quantity of silicon introduced not exceeding 300 g per tonne of steel treated.
  • the envelope of the cored wire is made of steel. Most often, about 125 to 600 g of calcium are introduced into the liquid steel, by means of this cored wire, per ton of steel treated.
  • the cored wire advantageously comprises a core of divided material which is in the compacted state inside the envelope, the latter having at least two parallel flattened zones, facing one another.
  • the grain calcium used is obtained by the process which is the subject of international PCT application WO 81/01811.
  • This process consists of melting the starting calcium and then passing it in the divided state through a purification bath, then, after settling, spraying it by passage through a vibrating orifice and finally solidifying the drops obtained in grains.
  • the invention applies particularly well to the continuous casting of steels.
  • the injection of the cored wire for the above treatment can be carried out either in a bag or in a distributor.
  • the process according to the invention most often applies to the production of unalloyed or weakly alloyed steels.
  • the method according to the invention makes it possible to carry out particularly economical addition of calcium in a steel, at the desired concentration to obtain globularization of the inclusions, while keeping the silicon content below a limit level, generally fixed by a standard.
  • a steel is thus obtained which, while having the characteristics specific to steels treated with calcium, in particular good isotropy of mechanical properties and excellent machinability, also exhibits excellent aptitude for cold deformation and more particularly stamping.
  • the quantities of silicon that can be introduced into the steel are also determined without exceeding the maximum acceptable limit.
  • This limit is most often around 20 to 30 thousandths percent.
  • the production of steel made it possible to obtain a steel made it possible to obtain a liquid steel with a very low silicon content, for example less than 5 thousandths percent it is possible to accept an increase of the silicon content of the steel during the introduction of the cored wire into the liquid steel of about 15 to 30 thousandths percent according to the specifications which the steel must meet. It is therefore possible to introduce into the steel, taking into account its initial silicon content and the limit fixed by the specification, 150 to 300 g of silicon per tonne of liquid steel.
  • this silicon is introduced in the form of a common type of calcium calcium, containing approximately in mass% Si 60, Ca 30 and Fe + impurities 10, it can be seen that the total amount of calcium calcium to be introduced is from 250 to 500 g per tonne of liquid steel. The corresponding amount of calcium thus introduced is 75 to 150 g per ton. It is enough to mix with calcium silica the calcium supplement in grain allowing to reach the quantity of total calcium which it acts to introduce. We can thus minimize the cost of developing such steels.
  • the invention also relates to a cored wire for the implementation of the method described above comprising a metal envelope inside which is enclosed a divided material based on calcium and silicon.
  • This divided material comprises at least two components, the first being metallic calcium in grains of which the content of particles smaller than the meshes of the sieve of 150 mesh does not exceed 2 to 3% by weight of said component, the second being of silico-calcium containing in mass% Ca 25 to 35%, Si 50 to 70%, Fe and impurities 5 to 15%, the ratio k between the contents of the first and second components being between 0.1 and 3 and preferably 0, 3 and 2.
  • the envelope of the cored wire according to the invention is made of steel.
  • a particularly advantageous solution for producing the cored wire is constituted by a wire whose envelope has at least two flattened parallel zones opposite one another.
  • This figure gives the ordinate the enrichment of the metal with silicon by injecting the cored wire as a function of the average calcium content of the mixture used.
  • the value K O corresponds to a divided material composed only of calcium calcium with 30% calcium. This value defines the starting points (5), (6) and (7) of each of the curves (1), (2) and (3).
  • the divided matter is constituted respectively by 1.5-1 and 0.5 kg of silico-calcium without addition of pure calcium.
  • the corresponding quantities of silicon which will be introduced into the liquid steel are: 900 g - 600 g and 300 g of silicon per tone.
  • the introduction yield of this silicon being practically 100% it is seen that these additions of silico-calcium enrich the steel in silicon respectively at these points by 90, 60 and 30 thousandths percent.
  • Such enrichments are not acceptable if one wishes to limit the final silicon content to a level for example less than 30 thousandths percent or even less than 25 or 20 thousandths percent.
  • the curves in the figure show that it is possible, by moderate enrichment in pure calcium of the divided matter, to lower the silicon content to the desired level. It can be seen, for example, that a mixture of divided matter having a ratio K of 0.6, that is to say in which the mass of pure calcium is equal to 60% of the mass of silico-calcium, makes it possible to divide by three silicon enrichment all other things being equal. Such a mixture contains 56% of Ca instead of 30% in the case of silico-calcium alone, and the mass necessary to treat a ton of liquid steel does not represent more than 53.6% of the initial mass.
  • K ratio of which can vary as required between 0.1 and 3.
  • K ratios can vary as required between 0.1 and 3.
  • K ratios can vary as required between 0.1 and 3.
  • K ratios can vary as required between 0.2 and 2. It is preferable to seek the use of K ratios as low as possible according to the aim sought so as to minimize the cost of the addition.
  • a steel for stamping is produced in known manner by means of an LD converter which, after pouring into a pocket, with dolomite coating, has the following composition in% by mass:
  • Calming in the ladle is carried out with aluminum without the addition of ferro-silicon.
  • This steel is treated in the ladle with a basic slag consisting of a mixture of alumina lime and fluorspar with agitation by blowing argon through a porous plug placed in the bottom of the ladle. After 10 minutes of blowing, the composition of the steel is as follows in% by mass:
  • the amount of silico-calcium introduced is 1.2 kg (corresponding to 0.36 kg of calcium) per tonne of liquid steel.
  • the steel is poured into ingots which are then transformed into slabs.
  • the average composition of these is then as follows in% by mass:
  • a steel for stamping is also produced by the process according to the invention, for which the specification imposes a silicon content of less than 0.020%.
  • a cored wire with a steel casing is then introduced into the liquid steel, the divided material of which is a mixture of silico-calcium of the same composition as for the first preparation, and of pure calcium in grains.
  • the ratio K is equal to 1.33, which corresponds to a divided material whose average calcium content is 70%.
  • the amount of total calcium added is the same as in the first case, that is to say 360 g / t of liquid steel to be treated.
  • the divided matter mixture contains 294 g of pure calcium in grains, 221 g of silico-calcium containing only 132 g of silicon.
  • the mass of mixture to be introduced is reduced to 515 g / t instead of 1200 g / t, which significantly reduces the length of the cored wire.
  • the steel obtained by the process according to the invention therefore conforms to the specification relating to the silicon content. It has a substantially isotropic structure, a very good drawing ability.
  • the invention makes it possible to determine in each case the optimal amounts of calcium and of silico-calcium to be used to obtain a drawing steel under the most economical conditions.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Treatment Of Steel In Its Molten State (AREA)
  • Continuous Casting (AREA)
  • Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
  • Heat Treatment Of Steel (AREA)
  • Heat Treatment Of Sheet Steel (AREA)
  • Chemical Treatment Of Metals (AREA)
EP84420156A 1983-09-20 1984-09-19 Procédé de traitement de l'acier par le calcium permettant d'obtenir une grande aptitude à la mise en forme à froid et une basse teneur en silicium Expired - Lifetime EP0141760B2 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT84420156T ATE26307T1 (de) 1983-09-20 1984-09-19 Verfahren zur calciumbehandlung von stahl zur erhoehung der kaltverformungsfaehigkeit und zur lenkung des siliziumgehaltes.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8315191A FR2552107B1 (fr) 1983-09-20 1983-09-20 Procede de traitement de l'acier par le calcium permettant d'obtenir une grande aptitude a la mise en forme a froid et une basse teneur en silicium
FR8315191 1983-09-20

Publications (3)

Publication Number Publication Date
EP0141760A1 EP0141760A1 (fr) 1985-05-15
EP0141760B1 EP0141760B1 (fr) 1987-04-01
EP0141760B2 true EP0141760B2 (fr) 1990-10-03

Family

ID=9292497

Family Applications (1)

Application Number Title Priority Date Filing Date
EP84420156A Expired - Lifetime EP0141760B2 (fr) 1983-09-20 1984-09-19 Procédé de traitement de l'acier par le calcium permettant d'obtenir une grande aptitude à la mise en forme à froid et une basse teneur en silicium

Country Status (8)

Country Link
US (1) US4555265A (enrdf_load_stackoverflow)
EP (1) EP0141760B2 (enrdf_load_stackoverflow)
JP (1) JPS6089514A (enrdf_load_stackoverflow)
AT (1) ATE26307T1 (enrdf_load_stackoverflow)
CA (1) CA1227335A (enrdf_load_stackoverflow)
DE (1) DE3462926D1 (enrdf_load_stackoverflow)
ES (1) ES8607409A1 (enrdf_load_stackoverflow)
FR (1) FR2552107B1 (enrdf_load_stackoverflow)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2166550C2 (ru) * 1999-03-26 2001-05-10 Центральный научно-исследовательский институт черной металлургии им. И.П. Бардина Способ производства низкокремнистой стали
RU2156308C1 (ru) * 1999-07-07 2000-09-20 ОАО "Новолипецкий металлургический комбинат" Способ обработки стали в ковше
RU2201458C1 (ru) * 2002-06-04 2003-03-27 ООО "Сорби стил" Способ модифицирования стали
FR2871477B1 (fr) 2004-06-10 2006-09-29 Affival Sa Sa Fil fourre
RU2465340C1 (ru) * 2011-07-08 2012-10-27 Открытое акционерное общество "Магнитогорский металлургический комбинат" Способ производства низкокремнистой стали
RU2495139C1 (ru) * 2012-05-14 2013-10-10 Открытое акционерное общество "Магнитогорский металлургический комбинат" Способ производства низкоуглеродистой стали
FR3006695A1 (fr) 2013-06-10 2014-12-12 Mourad Toumi Procede et dispositif de traitement d'un metal ou d'un alliage metallique en fusion par une substance additive
RU2532793C1 (ru) * 2013-10-03 2014-11-10 Открытое акционерное общество "Северский трубный завод" Смесь для обработки стали в ковше
RU2562849C1 (ru) * 2014-06-11 2015-09-10 Федеральное государственное бюджетное учреждение науки Институт металлургии Уральского отделения Российской академии наук (ИМЕТ УрО РАН) Шлаковая смесь для обработки стали в ковше
RU2607877C2 (ru) * 2015-06-10 2017-01-20 Открытое акционерное общество "Волжский трубный завод" Способ внепечной обработки стали
RU2735697C1 (ru) * 2020-03-24 2020-11-06 Федеральное государственное бюджетное учреждение науки Институт металлургии Уральского отделения Российской академии наук (ИМЕТ УрО РАН) Способ внепечной обработки стали в ковше

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
LU58377A1 (enrdf_load_stackoverflow) * 1969-04-04 1969-07-16
US3915693A (en) * 1972-06-21 1975-10-28 Robert T C Rasmussen Process, structure and composition relating to master alloys in wire or rod form
US3841616A (en) * 1973-12-10 1974-10-15 Metallurg Exoprod Corp Protective alloy addition apparatus
LU73229A1 (enrdf_load_stackoverflow) * 1974-08-21 1976-03-02
JPS5133761A (ja) * 1974-09-17 1976-03-23 Saito Kosakusho Kk Surasutobearingureesu no atsushukuseikeihoho
US4094666A (en) * 1977-05-24 1978-06-13 Metal Research Corporation Method for refining molten iron and steels
FR2471827A1 (fr) * 1979-12-21 1981-06-26 Extramet Sa Dispositif pour la production de granules metalliques uniformes
FR2476542B1 (enrdf_load_stackoverflow) * 1980-02-26 1983-03-11 Vallourec

Also Published As

Publication number Publication date
ATE26307T1 (de) 1987-04-15
ES536043A0 (es) 1986-05-16
CA1227335A (fr) 1987-09-29
DE3462926D1 (en) 1987-05-07
JPS6089514A (ja) 1985-05-20
FR2552107B1 (fr) 1985-12-20
EP0141760A1 (fr) 1985-05-15
ES8607409A1 (es) 1986-05-16
JPH0341524B2 (enrdf_load_stackoverflow) 1991-06-24
EP0141760B1 (fr) 1987-04-01
FR2552107A1 (fr) 1985-03-22
US4555265A (en) 1985-11-26

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