EP0061749B1 - Feinungsperiode bei einem mehrstufigen Stahlerzeugungsverfahren - Google Patents

Feinungsperiode bei einem mehrstufigen Stahlerzeugungsverfahren Download PDF

Info

Publication number
EP0061749B1
EP0061749B1 EP19820102580 EP82102580A EP0061749B1 EP 0061749 B1 EP0061749 B1 EP 0061749B1 EP 19820102580 EP19820102580 EP 19820102580 EP 82102580 A EP82102580 A EP 82102580A EP 0061749 B1 EP0061749 B1 EP 0061749B1
Authority
EP
European Patent Office
Prior art keywords
reaction vessel
pig iron
decarburization
melt
molten pig
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
Application number
EP19820102580
Other languages
English (en)
French (fr)
Other versions
EP0061749A1 (de
Inventor
Nishimura C/O Nippon Steel Corporation Mitsuhiko
Sakurada C/O Nippon Steel Corporation Morikatsu
Omori C/O Nippon Steel Corporation Masanao
Takeda C/O Nippon Steel Corporation Katsuhiko
Kojima C/O Nippon Steel Corporation Masamichi
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.)
Nippon Steel Corp
Original Assignee
Nippon Steel Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from JP56047023A external-priority patent/JPS57161018A/ja
Priority claimed from JP8933181A external-priority patent/JPS57203711A/ja
Priority claimed from JP8933381A external-priority patent/JPS57203713A/ja
Application filed by Nippon Steel Corp filed Critical Nippon Steel Corp
Publication of EP0061749A1 publication Critical patent/EP0061749A1/de
Application granted granted Critical
Publication of EP0061749B1 publication Critical patent/EP0061749B1/de
Expired legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D1/00—Treatment of fused masses in the ladle or the supply runners before casting
    • B22D1/002—Treatment with gases
    • B22D1/005—Injection assemblies therefor
    • 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
    • C21C1/00—Refining of pig-iron; Cast iron
    • 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
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/28—Manufacture of steel in the converter
    • C21C5/285—Plants therefor
    • 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
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/56—Manufacture of steel by other methods
    • C21C5/567—Manufacture of steel by other methods operating in a continuous way
    • 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
    • C21C1/00—Refining of pig-iron; Cast iron
    • C21C1/04—Removing impurities other than carbon, phosphorus or sulfur

Definitions

  • the present invention relates to a multi-step steelmaking refining method, comprising refining steps, beginning when the molten pig iron is tapped from the blast furnaces and ending when the molten steel is cast, carried out in a single reaction vessel, wherein the decarburization of molten pig iron, which has been desiliconized and dephosphorized, is carried out in the reaction vessel by means of oxygen which is soft-blown onto the surface of the molten pig iron by a multi-aperture lance or a plurality of lances while a stirring fluid is blown beneath the level of the molten pig iron within said reaction vessel during the decarburization treatment.
  • the impurities of molten pig iron produced by a blast furnace are removed exclusively in a converter, according to the conventional steelmaking refining method, by means of pure-oxygen being blown into the converter.
  • the function of removing the impurities is concentrated on the converter refining. More specifically, the desiliconization, dephosphorization, desulfurization and decarburization reactions proceed in a converter concurrently or successively to one another. Since the impurities to be removed have chemical properties different from each other, and since the removal reactions take place concurrently or successively, it is not always possible for the conditions in a converter to be suitable for the removal of each impurity to be removed.
  • silicon which is one of the impurities to be removed, is oxidized to Si0 2 usually in the initial oxygen-blowing period of a converter so that a slag layer having a low basicity (the ratio of CaO/SiO 2 ) is formed.
  • This slag having a low basicity is not suitable for the removal of phosphorus and sulfur.
  • the basicity of the slag In order to carry out the dephosphorization and desulfurization, the basicity of the slag must be maintained at a high level.
  • auxiliary materials mainly composed of lime, is incorporated in a converter. This causes the generation of an enormous amount of slag, for example, from 100 to 130 kg per ton of molten steel, which, in turn, brings about the following problems.
  • Desulfurization can be carried out at any time of the steelmaking refining method. For example, desulfurization can be carried out either once or twice simultaneously with the dephosphorization step, between the desiliconization and dephosphorization steps, or after the decarburization step. Even in this most advanced multi-step steelmaking refining method however, decarburization is accomplished in a conventional converter after the pretreatment of the molten pig iron for removing silicon, and phosphorus and occasionally sulfur in a ladle or torpedo car has been completed.
  • a multi-step steelmaking refining method comprising a desiliconization step, desulfurization and dephosphorization and a step to decarburize the molten iron whose silicon, sulfur and phosphorus contents have been reduced and it is known from FR-A-2 439 821 to blow the gaseous oxygen softly onto the surface of the bath, while simultaneously a gas is blowing into the reaction vessel from the bottom in order to stir the bath of molten iron vigorously.
  • the soft blowing can be performed by a single or a multi-aperture lance.
  • the molten pig iron which is the starting material of the decarburization treatment, is a pretreated molten pig iron which has been desiliconized and dephosphorized and, occasionally, has also been desulfurized to a predetermined level.
  • the molten pig iron subjected to the pretreatment mentioned above has a silicon content of usually not less than 0.20%, and desirably only a trace, and also has a phosphorus content not exceeding the value specified regarding the finished steel.
  • the present invention is not limited to a specific pretreatment method, and any known pretreatment method can be carried out.
  • any known treatment of decarburization steel may be carried out in the multi-step steelmaking refining method of the present invention.
  • This treatment which is carried out after the decarburization treatment, is hereinafter referred to as a post treatment.
  • the sulfur content can be decreased to a value lower than the value specified for the finished steel by means-of the following methods, which are selected depending upon the specific purpose of the steel. That is, the molten pig iron can be subjected to a desulfurization pretreatment, a desulfurization post treatment, or a combination of the desulfurization-pretreatment and post treatment, which combination is employed for producing high grade steels required to have a low sulfur content.
  • spitting is likely to occur when decarburization blowing is carried out when no slag, or only a small amount of slag, is present on the surface of the melt.
  • soft blow in which oxygen is calmly blown and transmitted to the surface of the melt, effectively suppresses spitting.
  • oxygen top blowing is carried out by a super soft blow, which cannot achieve effective decarburization in the conventional converter steelmaking method. It is also possible to drastically suppress spitting, while the decarburization reaction is effectively promoted, due to the stirring explained in detail hereinbelow.
  • decarburizing is accomplished in a short period of time in carrying out oxygen top blowing by means of a multi-aperture lance and/or a plurality of lances, thereby dispersing the oxygen jet on the surface of the melt and thus decreasing the depth of the cavity formed by the oxygen jet (L) of the oxygen jet into the melt.
  • oxygen is supplied to the melt at a high rate and the advantages of the super soft blow are maintained.
  • the oxygen jet is required to have both a function of supplying oxygen to cause the refining reactions and a function of stirring the melt so as to enhance the reaction efficiency.
  • the oxygen jet of the conventional converter steelmaking method therefore, involves a problem in that the stirring function, which should enhance and promote the reaction, leads instead to spitting.
  • the two functions of the oxygen jet mentioned above, are distinctly divided so that the top blowing oxygen jet is provided only to supply the oxygen and a stirring fluid is employed only to stir the melt.
  • the super soft blow is so inadequate for stirring molten pig iron that a large iron oxide layer tends to form on the surface of the melt, and, further, the ratio of supplied oxygen combining with the carbon during decarburization, which is referred to as the decarburization reaction ratio, is decreased.
  • the decarburization reaction ratio the ratio of supplied oxygen combining with the carbon during decarburization
  • the stirring fluid is blown through one or more immersion lances.
  • the stirring fluid is blown through one or more of tuyeres or gas-permeable plugs situated in the reaction vessel beneath the level of the molten pig iron.
  • the blowing rate of the stirring fluid must be such that a stirring state, in terms of stirring power, of at least 400 watt/ton, preferably at least 800 watt/ton, be ensured.
  • the stirring power is calculated by the following equation wherein:
  • the decarburization blowing in which spitting is drastically suppressed due to the super soft blow, is advantageously achieved in the present invention, and, therefore, a considerably greater amount of molten pig iron can be loaded in a converter than that able to be loaded in a conventional converter refining method.
  • the reaction vessel mentioned above is a ladle for molten pig iron, which may be provided with a means for blowing the stirring fluid, and this ladle contains the molten pig iron in a filling ratio which is of a usual value.
  • the usual amount of molten pig iron loaded in a pig iron ladle for example from 60 to 80% based on the volume of the pig iron ladle, is considerably higher than the usual amount of molten pig iron loaded in a converter according to a conventional decarburization blowing method.
  • the decarburization blowing method according to said embodiment is carried out under a high loading condition, the decarburization blowing can be carried out effectively without causing a decrease in the recovery of iron. It is therefore unnecessary according to the decarburization blowing method of the present invention, to use such an excessively large apparatus as a converter, since the steelmaking refining steps can be effectively carried out in a compact apparatus or apparatuses.
  • the steps starting at receiving the molten pig iron from a blast furnace and ending at the casting of the molten steel can be carried out. These steps may include successively the desiliconization step, the dephosphorization or simultaneous dephosphorization and desulfurization step, and the decarburization step.
  • the reaction vessel such as a molten pig iron ladle, has both a role of transporting the melt and a role of supplying a place where the refining reactions take place.
  • the desiliconization step and the dephosphorization, or simultaneous dephosphorization and desulfurization step can be successively carried out in the torpedo cars, and subsequently, before the initiation of the decarburization step, the molten pig iron is reloaded from the torpedo cars into a reaction vessel, which is a reaction vessel other than the torpedo cars.
  • the decarburization blowing is then carried out in the reaction vessel.
  • the desulfurization and adjusting of the steel chemistry can be carried out in this reaction vessel, followed by a casting step.
  • the melt must be reloaded once.
  • this method is also advantageous, because the decarburization step is carried out according to the present invention.
  • Methods for decreasing the times of reloading the melt or making the reloading unnecessary are previously known.
  • a ladle receives the molten pig iron tapped and this molten pig iron is directly loaded in a converter without reloading of the melt.
  • molten pig iron which has been desiliconized, dephosphorized and desulfurized in one vessel, is decarburized in a converter.
  • refining is continuously carried out in a transportable refining ladle.
  • the stirring fluid is at least one member selected from the group consisting of carbon dioxide gas, argon, nitrogen gas and oxygen gas.
  • the nitrogen gas should not be used for producing a grade of steel in which the nitrogen content is required to be very low. Since the oxygen may erode the refractories of the gas-permeable plugs, the cooling of such plugs is advisable.
  • a removable free board is installed on the reaction vessel at the decarburization period.
  • a characteristic parameter of the oxygen jet (UL o ) cannot be more than 0.3, wherein L o is the depth of a stationary melt within a reaction vessel in mm and L is the depth of the cavity formed by the oxygen jet in mm determined by the following formulae.
  • k 1.0.
  • n 2 or more (n?2)
  • the depth of a stationary melt within a converter (L o ) is, at the highest, from approximately 0.1 to 0.3 times the effective inner height of the converter (L t ), and, therefore, most of the effective inner height (L t ) of the converter is a so-called free board, where the converter wall does not come in contact with the melt.
  • the ratio of L ° /L t can be 0.6 or more (L ° /L t ⁇ 0.6). In this case, the maximum ratio of L ° /L t is limited, so that height of the melt, which is stirred due to the decarburization blowing, does not exceed the height of the free board.
  • the decarburization blowing is possible, even in a case when L ° /D ° ⁇ 0.5.
  • the decarburization treatment capacity of a reaction vessel having a predetermined dimension can be significantly increased, as compared with that in the conventional converter refining method, which is a commercially useful point.
  • liquid such as liquid oxygen and liquid carbon dioxide
  • mixture of a gas and a liquid can be used as the stirring fluid.
  • the volume expansion at the gasification of the liquid is highly effective for stirring the melt.
  • the multi-step steelmaking refining method of the present invention comprises a novel decarburization step-which does not rely at all on the conventional converter steelmaking method. Since one of the advantages of the present invention resides in a very simplified process starting at the receipt of the molten pig iron from a blast furnace and ending at the pouring and solidification of the steel, the present invention is greatly advantageous to the steelmaking industry.
  • reaction vessel has the roles of transporting, storing, pouring and being the place where the refining reactions take place.
  • stations of refining, casting and the like are arranged linearly, while in Fig. 2 these stations are arranged in a circle.
  • the reaction vessel is composed of the metal shell 1a and refractory lining 1 b and contains therein the melt 2.
  • the depth of the melt 2 is L o when the melt is stationary.
  • the reaction vessel has the effective inner height L t which is shown in Fig. 3.
  • the oxygen is blown through the top blowing lance 3 by a super soft blow.
  • One gas-permeable refractory plug 4 is provided at the bottom of the reaction vessel 1 so as to blow the stirring fluid into the melt 2.
  • the oxygen blown from the top blowing lance 3 makes the cavities onto the melt 2 by a depth of L.
  • the melt 2 is basically molten pig iron, since if the slag forming agent is used, it is used only to the extent that the oxides resultant from the oxygen blowing cannot erode the refractory lining 1 b.
  • the symbols of HF and Do in Fig. 3 denote the height of the freeboard and the effective inner diameter of the reaction vessel. If necessary, a plurality of the top blowing lances 3 and a plurality of the gas-permeable refractory plugs may be used.
  • FIG. 4 three top blowing lances 3 are used for blowing the oxygen and the bottom of reaction vessel 1 is provided with two blowing tuyeres 5 instead of the gas-permeable refractory plug 4 for blowing the stirring fluid.
  • two top blowing lances 3 are used for oxygen blowing and the stirring fluid is blown through the immersion lance 6.
  • a removable side wall, i.e. free board 7, is installed on the reaction vessel, so as to form an inner space 8 defined by the inner wall of the free board 7 and thus spitting of melt 2 out of the inner space 8 is prevented.
  • the present invention and conventional methods having different ratios of LJL, different from one another are compared with one another regarding the amount of melt scattered out of the reaction vessel and the variation of the decarburization reaction ratio vary depending upon the characteristic parameter of oxygen jet (UL o ).
  • the ratios of LolL! of the present invention and conventional methods are 0.7 and 0.2, respectively.
  • the characteristic parameter of oxygen jet (UL o ) is usually set between 0.7 and 1.0.
  • the super soft blow of present invention in terms of characteristic parameter of oxygen jet (UL o ) is not more than 0.3, which isthe preferable maximum value for keeping the recovery of iron, and the decarburization reaction in the conventional converter steelmaking method virtually does not take place. More specifically, the term "super soft blow” can be explained by the concept that the decarburization reaction ratio is virtually zero when the melt is not subjected to stirring by the stirring fluid blown into the melt.
  • the decarburization reaction ratio is at the ideal level. This is because the oxygen is brought into a direct contact with the melt and the stirring mentioned above is carried out.
  • Table 1 shows the average steel chemistry of six heats, when the multi-step steelmaking method comprising the desiliconization, simultaneous dephosphorization and desulfurization, and decarburization steps were carried out. Each heat consisted of 60 ton of molten pig iron and 6 ton of scraps. An increase in the phosphorus content after the decarburization step is not considered to be the result of rephosphorization. The recovery of iron and the amount of slag generated are shown in Table 2.
  • Example 1 The procedure of Example 1 was repeated except for the decarburization step as is apparent from Table 3. The recovery of iron by the present invention is considerably higher than that of the comparative tests.
  • the multi-step refining method comprised the desiliconization, dephosphorization, decarburization and desulfurization steps.
  • the resultant steel chemistry and refining condition in each step are shown in Table 4, and the recovery of iron and amount of slag generated are shown in Table 5.
  • Example 3 The procedure of Example 3 was repeated except for the decarburization step as apparent from Table 6.
  • the - amount of slag generated is very small because no auxiliary raw materials are used at all, and the recovery of iron is high.
  • invention and “Conventional” indicate the decarburization blowing method, in which the liquid oxygen was blown as the stirring gas, and the decarburization blowing method, in which no stirring gas was blown, respectively.
  • an excessively large apparatus such as a converter
  • an increase in the recovery of iron can be achieved, according to the present invention. Since reloading of the melt is no longer necessary or if necessary, reloading is limited to only one or possibly two times, the generation of dust is decreased and thermal efficiency is increased. Since the amount of slag generated in accordance with the method of the present invention is considerably smaller that generated in the conventional converter steelmaking method, the slag processing apparatus can be very compact.
  • the free oxygen content of the steel at the end of the oxygen blowing process is lower as compared with that the conventional steelmaking method, which contributes to the recovery of alloying elements, as well as to the recovery of iron.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Botany (AREA)
  • Mechanical Engineering (AREA)
  • Carbon Steel Or Casting Steel Manufacturing (AREA)
  • Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)

Claims (7)

1. Feinungsperiode bei einem mehrstufigen Stahlerzeugungsverfahren, welches die Feinungsschritte umfaßt, beginnend, wenn das geschmolzene Roheisen von dem Hochofen abgestochen wird, und endend, wenn die Stahlschmelze gegossen ist, ausgeführt in einem einfachen Reaktionsgefäß, wobei die Entkohlung des geschmolzenen Roheisens, das endsiliciert und endphosphorisiert wurde, in dem Reaktionsgefäß mittels Sauerstoff durchgeführt wird, der weich auf die Oberfläche des geschmolzenen Roheisens durch eine Lanze mit vielen Öffnungen oder durch eine Vielzahl von Lanzen geblasen wird, während eine Rührflüssigkeit unter die Oberfläche des geschmolzenen Roheisens innerhalb des Reaktionsgefäßes während der Entkohlungsbehandlung geblasen wird, gekennzeichnet durch die Kombination des Blasens mit der Lanze oder den Lanzen und des Rührens mit einer Kraft (s) von nicht weniger als 400 Watt/Tonne nach der Gleichung (s)=0.0285 (Q. T/W) log (1+H/148), worin
Q die Fließgeschwindigkeit der Rührflüssigkeit in Liter/Minute,
T die Temperatur der Schmelze in °K,
W das Gewicht der Schmelze in Tonnen und
H die Tiefe der geblasenen Rührflüssigkeit in cm ist.
2. Verfahren nach Anspruch 1, worin die Rührflüssigkeit durch eine oder mehrere Eintauchlanzen (6) geblasen wird.
3. Verfahren nach Anspruch 1, worin die Rührflüssigkeit durch eine oder mehrere Düsen oder gasdurchlässige Stopfen (5) geblasen wird, die in dem Reaktionsgefäß (1) unter der Oberfläche des geschmolzenen Roheisens (2) angeordnet sind.
4. Verfahren nach einem der Ansprüche 1 bis 3, worin der charakteristische Parameter der Sauerstoffdüse (ULo) nicht mehr als 0,3 beträgt, wobei La die Tiefe einer feststehenden Schmelze innerhalb des Reaktionsgefäßes in mm und L die Tiefe des durch die Sauerstoffdüse geformten Hohlraums in mm ist.
5. Verfahren nach einem der Ansprüche 1 bis 3, worin die Tiefe einer feststehenden Schmelze innerhalb eines Konverters (La) beim kleinsten Wert das 0,6-fache der effektiven inneren Höhe des Konverters (Lt) beträgt.
6. Verfahren nach einem der Ansprüche 1 bis 3, worin das Verhältnis von L°/D°≧0,5 erfüllt ist, wobei Do der effektive innere Durchmesser des Reaktionsgefäßes ist.
7. Verfahren nach Anspruch 1, worin die Rührkraft nicht weniger als 800 Watt/Tonne beträgt.
EP19820102580 1981-03-30 1982-03-26 Feinungsperiode bei einem mehrstufigen Stahlerzeugungsverfahren Expired EP0061749B1 (de)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
JP47023/81 1981-03-30
JP56047023A JPS57161018A (en) 1981-03-30 1981-03-30 Refining method for molten iron
JP8933181A JPS57203711A (en) 1981-06-10 1981-06-10 Refining method in steel making
JP89333/81 1981-06-10
JP89331/81 1981-06-10
JP8933381A JPS57203713A (en) 1981-06-10 1981-06-10 Method of decarburization refining in reaction vessel with small free board

Publications (2)

Publication Number Publication Date
EP0061749A1 EP0061749A1 (de) 1982-10-06
EP0061749B1 true EP0061749B1 (de) 1986-02-26

Family

ID=27292844

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19820102580 Expired EP0061749B1 (de) 1981-03-30 1982-03-26 Feinungsperiode bei einem mehrstufigen Stahlerzeugungsverfahren

Country Status (3)

Country Link
EP (1) EP0061749B1 (de)
AU (1) AU532932B2 (de)
DE (1) DE3269285D1 (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2527634A1 (fr) * 1982-05-28 1983-12-02 Sumitomo Metal Ind Procede de production d'acier a teneur ultra-faible en phosphore
DE3316367A1 (de) * 1983-05-05 1984-11-08 Mannesmann AG, 4000 Düsseldorf Verfahren und einrichtung zum erzeugen von stahl
FR2558482A1 (fr) * 1984-01-25 1985-07-26 Siderurgie Fse Inst Rech Procede d'elaboration de l'acier par preaffinage de la fonte
DE3507785A1 (de) * 1984-03-14 1985-09-19 Aichi Steel Works, Ltd., Tokai, Aichi Lagerstahl und verfahren zu seiner herstellung
FR2566427A1 (fr) * 1984-06-22 1985-12-27 Siderurgie Fse Inst Rech Installation pour l'elaboration de l'acier par preaffinage de la fonte
EP0589366A1 (de) * 1992-09-25 1994-03-30 Marti Technologie Ag Stahlwerksanordnung

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
LU43212A1 (de) * 1962-04-24 1963-04-18
DE2522194A1 (de) * 1975-05-17 1976-12-02 Vacmetal Gmbh Verfahren und vorrichtung zum herstellen von qualitaetsstaehlen
US4295882A (en) * 1978-10-24 1981-10-20 Nippon Steel Corporation Steel making process

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2527634A1 (fr) * 1982-05-28 1983-12-02 Sumitomo Metal Ind Procede de production d'acier a teneur ultra-faible en phosphore
DE3316367A1 (de) * 1983-05-05 1984-11-08 Mannesmann AG, 4000 Düsseldorf Verfahren und einrichtung zum erzeugen von stahl
EP0124890A1 (de) * 1983-05-05 1984-11-14 MANNESMANN Aktiengesellschaft Verfahren und Einrichtung zum Erzeugen von Stahl
FR2558482A1 (fr) * 1984-01-25 1985-07-26 Siderurgie Fse Inst Rech Procede d'elaboration de l'acier par preaffinage de la fonte
DE3507785A1 (de) * 1984-03-14 1985-09-19 Aichi Steel Works, Ltd., Tokai, Aichi Lagerstahl und verfahren zu seiner herstellung
FR2566427A1 (fr) * 1984-06-22 1985-12-27 Siderurgie Fse Inst Rech Installation pour l'elaboration de l'acier par preaffinage de la fonte
EP0166646A1 (de) * 1984-06-22 1986-01-02 Institut De Recherches De La Siderurgie Francaise (Irsid) Vorrichtung zur Herstellung von Stahl durch Vorfrischen von Roheisen
EP0589366A1 (de) * 1992-09-25 1994-03-30 Marti Technologie Ag Stahlwerksanordnung

Also Published As

Publication number Publication date
DE3269285D1 (en) 1986-04-03
EP0061749A1 (de) 1982-10-06
AU532932B2 (en) 1983-10-20
AU8184882A (en) 1982-11-04

Similar Documents

Publication Publication Date Title
US4295882A (en) Steel making process
EP0017963B1 (de) Verfahren zum Herstellen von Stahl im Konverter
CA1166018A (en) Steelmaking process with separate refining steps
EP0061749B1 (de) Feinungsperiode bei einem mehrstufigen Stahlerzeugungsverfahren
JPH044388B2 (de)
EP0033780B2 (de) Verfahren zur Auswurfverminderung beim Frischen im bodenblasenden Konverter
US4415359A (en) Multi-step steelmaking refining method
EP0073274B1 (de) Verfahren zum Vorentsilizieren von Eisenschmelzen durch Einblasen von gasförmigen Sauerstoff
JP3333339B2 (ja) 脱炭滓をリサイクルする転炉製鋼法
CA1205290A (en) Method of increasing the cold material charging capacity in the top-blowing production of steel
JP3486886B2 (ja) ２基以上の転炉を使用する製鋼方法
JPH08311519A (ja) 転炉製鋼法
US4525209A (en) Process for producing low P chromium-containing steel
EP0159517B1 (de) Stahlerzeugungsverfahren mit Schnellentkohlung
JPS6056051A (ja) 中・低炭素フエロマンガンの製造方法
JPH1150122A (ja) 転炉型精錬容器における溶銑の脱燐精錬方法
JPH0860221A (ja) 転炉製鋼法
US4065297A (en) Process for dephosphorizing molten pig iron
US3782921A (en) Production of steel with a controlled phosphorus content
JPS625964B2 (de)
SU1712424A1 (ru) Способ выплавки высокоуглеродистой стали дл высокопрочной проволоки
US4451288A (en) Method for producing low hydrogen content in steels produced by subsurface pneumatic refining
SU1604165A3 (ru) Способ производства стали в конвертере
JPH09256020A (ja) 転炉型精錬容器における溶銑の脱燐精錬方法
JPS61104014A (ja) 酸化精錬炉におけるＭｎ鉱石高効率還元法

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19820326

AK Designated contracting states

Designated state(s): BE DE FR GB

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): BE DE FR GB

REF Corresponds to:

Ref document number: 3269285

Country of ref document: DE

Date of ref document: 19860403

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19950309

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19950316

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19950322

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 19950510

Year of fee payment: 14

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19960326

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Effective date: 19960331

BERE Be: lapsed

Owner name: NIPPON STEEL CORP.

Effective date: 19960331

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19960326

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19961129

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19961203

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST