EP0328851A1 - Appareillage pour la décarburation des aciers directement dans une poche - Google Patents

Appareillage pour la décarburation des aciers directement dans une poche Download PDF

Info

Publication number
EP0328851A1
EP0328851A1 EP88830057A EP88830057A EP0328851A1 EP 0328851 A1 EP0328851 A1 EP 0328851A1 EP 88830057 A EP88830057 A EP 88830057A EP 88830057 A EP88830057 A EP 88830057A EP 0328851 A1 EP0328851 A1 EP 0328851A1
Authority
EP
European Patent Office
Prior art keywords
lid
ladle
injector
pool
vessel
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.)
Withdrawn
Application number
EP88830057A
Other languages
German (de)
English (en)
Inventor
Giorgio Enrico Falck
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.)
ACCIAIERIE E FERRIERE LOMBARDE FALCK SpA
Original Assignee
ACCIAIERIE E FERRIERE LOMBARDE FALCK SpA
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
Application filed by ACCIAIERIE E FERRIERE LOMBARDE FALCK SpA filed Critical ACCIAIERIE E FERRIERE LOMBARDE FALCK SpA
Priority to EP88830057A priority Critical patent/EP0328851A1/fr
Publication of EP0328851A1 publication Critical patent/EP0328851A1/fr
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • 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
    • C21C7/068—Decarburising
    • C21C7/0685—Decarburising of stainless steel
    • 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
    • C21C7/10—Handling in a vacuum

Definitions

  • This invention relates to an apparatus for decarbonizing steels directly in the ladle. More particularly, the invention is concerned with an apparatus for processing and hard vacuum decarbonizing steels, specifically high alloyed and stainless steels, in the ladle, of a type which comprises a vessel adapted to receive a ladle containing a pool of molten steel having its free surface to a set level, and a lid secured on said vessel in a removable tight manner.
  • the vacuum degassing step in the ladle has shown to be quite effective to lower the hydrogen content of steels, and accordingly, remove the risk of flaking in a rapid and economical way.
  • Such conventional apparatus for vacuum treating in the ladle are often further equipped with devices for additivating the molten steel with components as required to produce a desired alloy, and with carbon electrodes which are mounted slidingly through the vessel lid to heat the steel pool by means of a three-phase arc and maintain the pool at a set temperature.
  • the problem which underlies this invention is to provide an apparatus as indicated for processing and hard vacuum decarbonizing steels in the ladle, which has such constructional and operational features as to overcome the drawbacks affecting the state of the art.
  • an apparatus of the type specified hereinabove being characterized in that it comprises a supersonic oxygen injector mounted through the lid and extending toward the ladle in spaced apart relationship with said free surface to blow oxygen through the steel pool.
  • the numeral 1 designates generally an apparatus for processing and hard vacuum decarbonizing special steels, specifically high alloyed and stainless steels, in the ladle.
  • the apparatus 1 comprises a vessel 2 having a substantially cylindrical shape and an open top, inside which vessel a ladle 3 is supported which contains a pool 4 of a molten steel to be treated having a free surface 4a at a set level within the ladle 3.
  • a porous plug mounted at the bottom 3a of the ladle 3, a means, not shown, being provided to blow a noble gas, preferably argon, through the molten steel pool 4 via the porous plug 5.
  • a noble gas preferably argon
  • the apparatus 1 further comprises a lid 6 which is secured on the vessel 2 in a removable tight manner; in particular, the lid 6 is movable vertically toward and away from said vessel 2 by the action of a drive known per se and omitted therefore from the drawing.
  • the numeral 8 designates three identical electrodes which are connected to an electric circuit and consist of graphite bars laid vertically and inserted slidingly through the lid 6 at a central location thereon overlying the ladle 3. Sliding seals are provided which fit around each electrode 8 at the lid 6.
  • the electrodes 8 are mounted inside respective vacuum tight telescoping tubes 9 carried in a position overlying the lid 6; further, the electrodes 8 can be driven vertically toward and away from the steel pool 4 by a motor means known per se, and accordingly omitted from the drawing, to heat the pool by means of a three-phase arc, thereby maintaining the steel temperature at a set level.
  • a shield 10 is suspended in the lid 6 above the ladle 3 and is formed with three ports 11 to admit the three electrodes 8 therethrough, and with a port 12 which is offset from the ports 11.
  • the apparatus 1 includes a supersonic oxygen injector 13 mounted through the lid 6 in sealed relationship with it and by the side of the electrodes 8, which extends through the port 12 toward the ladle 3 to blow oxygen, at a pressure of up to about 588.393 kPa, onto the pool 4 of molten steel.
  • the injector 13 has a body 14 of tubular shape and is provided with a nozzle 15 at a bottom end thereof.
  • Interspaces 30 are formed in the body 14 through which a cooling fluid is circulated.
  • the injector 13 is set at an inclination angle of approximately 45° from the vertical and is mounted slidingly through the lid 6, a vacuum seal means 16 being arranged to fit around the injector 13, and a motive means 17 being provided to move the injector 13 from an inoperative position where it is fully retracted into the lid 6 (cf. Figures 3 and 4) and an operative position where it projects toward the ladle 3 (cf. Figures 1 and 2) with the nozzle 15 at a set distance from the free surface 4a of the steel pool 4.
  • An annular seal 21 fits slidingly over the tube 18 and is associated with a bottom end 20b of the sleeve 20 by means of a ring-like flexible joint 21b fast with the seal 21 and mounted to the end 20b which is adapted to compensate for any slight misalignment between the tube 18 and the sleeve 20.
  • the sleeve 20 is mounted on a carriage 22 running along guides 23 provided on the lid 6 at an inclination angle of 45° and lying parallel to the tube 18.
  • the numeral 27 designates an oxygen supply conduit to the injector 13, which is connected to the top end 14a of the injector body 14, and at 28 and 29 there are indicated delivery and return conduits for the cooling fluid to/from the injector which are connected to the interspaces 30 at the top end 14a.
  • a screen 34 intended for shutting off, by the action of a motive means 35 known per se, the orifice 19 and protecting the injector 13 in the inoperative position thereof fully retracted into the lid 6.
  • the apparatus 1 also includes devices, not shown, which are mounted on the lid 6 for the purpose of adding components to the steel contained in the ladle 3.
  • the electrodes 8 are raised above the shield 10.
  • the injector 13 is then brought to the extended operative position with the nozzle 15 at a set distance above the free surface 4a of the pool 4, which is maintained under continued agitation by blowing in argon through the porous plug 5 in the bottom 3a of the ladle 3.
  • the injector 13 is operated to blow a jet of oxygen under pressure onto the pool 4.
  • the jet of oxygen is advantageously directed at an angle of about 45° toward a central area of the steel pool surface.
  • the pressure of the oxygen jet, together with its inclination angle and the distance of the nozzle 15 off the free surface 4a, is determined to force the jet deeply through the pool 4 so as to achieve optimum combustion of the carbon contained therein.
  • the distance of the nozzle 15 from the free surface 4a is controlled by moving the carriage 22 at a slow rate along the guides 23 by means of the drive 17.
  • the injector In operation, the injector would be constantly cooled by the coolant fluid circulated through the interspaces 30.
  • the injector 13 On completion of the decarbonizing step, the injector 13 is raised by means of the drive 17 to its inoperative position retracted into the lid 6, with the nozzle 15 positioned at the orifice 19 (cf. Figure 4).
  • the injector 13 would be kept in that inoperative position both with the lid 6 taken off the vessel 2 (cf. Figure 3) and, with the vessel closed by the lid 6, where the steel to be treated requires no hard decarbonizing, and where the electrodes 8 are to be lowered to heat the pool 4.
  • the inventive apparatus for processing and hard vacuum decarbonizing steels in the ladle has shown to be particularly useful to produce a wide range of special steels having a constant high qualitative level, while considerably shortening the times involved in their processing.
  • the ability to retract and protect the injector into the inoperative position whenever its use is not required affords flexible conditions of operation for the inventive apparatus, which can thus be used contingent on requirements to either produce steels requiring hard decarbonizing or steels which need no such decarbonization.
  • This apparatus moreover, lends itself to full automation, especially as relates to the position of the injector nozzle with respect to the free surface of the molten steel pool to be treated, whose level is often liable to change.
  • a second embodiment of this invention is advantageously provided as indicated at 101 in Figure 5.
  • the apparatus 101 comprises a ladle 102 containing a pool 4 of molten steel having a free surface 4a at a set level.
  • a lid secured removably and tightly on the ladle 102 in a manner known per se, a suction means being provided which is connected to a port 104 open inwardly of the lid 103 and can form within the ladle a set vacuum.
  • the apparatus 101 further comprises a supersonic oxygen injector 13 mounted in a sealed fashion through the lid 103 and extending into the ladle 102 in spaced apart relationship with said free surface 4a to blow oxygen through the molten steel pool 4.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Treatment Of Steel In Its Molten State (AREA)
EP88830057A 1988-02-16 1988-02-16 Appareillage pour la décarburation des aciers directement dans une poche Withdrawn EP0328851A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP88830057A EP0328851A1 (fr) 1988-02-16 1988-02-16 Appareillage pour la décarburation des aciers directement dans une poche

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP88830057A EP0328851A1 (fr) 1988-02-16 1988-02-16 Appareillage pour la décarburation des aciers directement dans une poche

Publications (1)

Publication Number Publication Date
EP0328851A1 true EP0328851A1 (fr) 1989-08-23

Family

ID=8200622

Family Applications (1)

Application Number Title Priority Date Filing Date
EP88830057A Withdrawn EP0328851A1 (fr) 1988-02-16 1988-02-16 Appareillage pour la décarburation des aciers directement dans une poche

Country Status (1)

Country Link
EP (1) EP0328851A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0514246A1 (fr) * 1991-05-13 1992-11-19 Sollac Procédé de décarburation d'acier dans une enceinte de traitement sous vide et enceinte de traitement sous vide pour la mise en oeuvre du procédé
AU653294B2 (en) * 1992-08-26 1994-09-22 Nippon Steel Corporation Process for vacuum degassing molten steel

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1904442A1 (de) * 1969-01-30 1970-09-03 Hoesch Ag Verfahren zum Frischen von Metallschmelzen
FR2098781A5 (en) * 1970-07-27 1972-03-10 Siderurgie Fse Inst Rech Lance position control device - for metallurgical refining vessels under high or low pressure
US4057421A (en) * 1974-10-22 1977-11-08 Sumitomo Metal Industries Limited Process for vacuum decarburization of steel

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1904442A1 (de) * 1969-01-30 1970-09-03 Hoesch Ag Verfahren zum Frischen von Metallschmelzen
FR2098781A5 (en) * 1970-07-27 1972-03-10 Siderurgie Fse Inst Rech Lance position control device - for metallurgical refining vessels under high or low pressure
US4057421A (en) * 1974-10-22 1977-11-08 Sumitomo Metal Industries Limited Process for vacuum decarburization of steel

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
MAN UNTERNEHMENSBEREICH GHH STERKRADE; "Secondary metallurgy" *
PATENT ABSTRACTS OF JAPAN, vol. 7, no. 108 (C-165)[1253], 11th May 1983; & JP-A-58 31 023 (SUMITOMO KINZOKU KOGYO K.K.) 23-02-1983 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0514246A1 (fr) * 1991-05-13 1992-11-19 Sollac Procédé de décarburation d'acier dans une enceinte de traitement sous vide et enceinte de traitement sous vide pour la mise en oeuvre du procédé
FR2676458A1 (fr) * 1991-05-13 1992-11-20 Lorraine Laminage Procede de decarburation d'acier dans une enceinte de traitement sous vide et enceinte de traitement sous vide pour la mise en óoeuvre du procede.
WO1992020986A1 (fr) * 1991-05-13 1992-11-26 Sollac Procede de decarburation d'acier dans une enceinte de traitement sous vide et enceinte de traitement sous vide pour la mise en ×uvre du procede
US5332417A (en) * 1991-05-13 1994-07-26 Sollac Method for decarburisation of steel in a vacuum treatment chamber and vacuum treatment chamber for implementing the method
AU653294B2 (en) * 1992-08-26 1994-09-22 Nippon Steel Corporation Process for vacuum degassing molten steel

Similar Documents

Publication Publication Date Title
CA1270503A (fr) Four-poche de coulee
EP0328851A1 (fr) Appareillage pour la décarburation des aciers directement dans une poche
US3777041A (en) Electroslag refining apparatus
CN86102142A (zh) 喷枪支承装置
US4456478A (en) Method of and apparatus for metallurgically treating molten metals
KR970005200B1 (ko) 진공에서 금속을 취급하기 위한 방법 및 장치
US5917115A (en) Apparatus for and method of treating liquid metal
US2474701A (en) Apparatus for decarburizing steel
JPH0674425A (ja) 多目的バーナ
KR100523797B1 (ko) 승온 기능을 구비한 진공 탱크 탈가스 장치 및 이를이용한 진공 탈가스 방법
JP3496284B2 (ja) 真空脱ガス槽内に挿入する水冷ランスおよびその閉塞防止方法
JP2974587B2 (ja) 真空脱ガス槽の槽内待機型バーナランス
JP3038783B2 (ja) 含クロム溶鋼用精錬装置
KR100270108B1 (ko) 용강처리시의 지금 제거장치 및 그 방법
US3669437A (en) Holder for an oxygen supply pipe
US4655826A (en) Method for post-melting treatment of molten steel
JP3742534B2 (ja) 減圧精錬装置およびそれを用いた低炭素鋼の溶製方法
KR100232912B1 (ko) 진공처리실에서의 강의 탄소제거방법 및 그 방법을 수행하기 위한 진공처리실
KR100398379B1 (ko) 진공탈가스설비에의한용강의탈탄방법
KR20050013423A (ko) 다기능 산소취입토치를 갖는 진공탈가스장치
JPH07113113A (ja) 取鍋内溶鋼の昇熱装置
JPH01268815A (ja) 溶鋼の真空脱ガス処理方法
JPH04168214A (ja) 極低炭素鋼の溶製方法及び、その装置
JPS6217008B2 (fr)
CN115287413A (zh) 一种rh炉真空槽冶金装置及方法

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

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE ES FR GB GR IT LI LU NL SE

17P Request for examination filed

Effective date: 19900205

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

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19920902