US3322530A - Method for adding additives to molten steel - Google Patents

Method for adding additives to molten steel Download PDF

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Publication number
US3322530A
US3322530A US304019A US30401963A US3322530A US 3322530 A US3322530 A US 3322530A US 304019 A US304019 A US 304019A US 30401963 A US30401963 A US 30401963A US 3322530 A US3322530 A US 3322530A
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Prior art keywords
steel
nitrogen
molten steel
pipe
ladle
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Expired - Lifetime
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US304019A
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English (en)
Inventor
Nakamura Hajime
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IHI Corp
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Ishikawajima Harima Heavy Industries Co Ltd
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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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12014—All metal or with adjacent metals having metal particles
    • Y10T428/12028—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, etc.]
    • Y10T428/12063—Nonparticulate metal component
    • Y10T428/12097—Nonparticulate component encloses particles
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12222—Shaped configuration for melting [e.g., package, etc.]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12986—Adjacent functionally defined components

Definitions

  • this inven-tion relates to a method for adding additives to molten steel refined by any way of oxidation refining or both oxidation and reduction refining, the steel being tapped to a ladle equipped with a suitable number of transport pipes in which the additives are provided or through which they are fed to said molten steel.
  • Said transport pipes are so designed as to be consumed in the molten steel from its lower end in approximate synchronism with the rise of said molten steel surface as the latter is accumulated in the ladle in such a manner as to release said additives gradually and steadily in a zone of 4the molten steel bath that is approximately constant in relative position with respect to the rising surface of said steel bath.
  • the primary purpose of this invention is to provide low carbon unalloyed steel, or low carbon low alloyed steel enriched with nitrogen, and also to provide a process to produce such steels economically and efiiciently as well as to provide a new steelmaking process in which the reduction refining may be carried out during and simultaneous with the tapping.
  • Other purposes and applications of this invention will be elucidated in the course of disclosure.
  • the nitrogen enrichment agent may be previously laid along the bottom of the ladle and the molten steel may be tapped onto said agent in the same way as commonly employed for adding various alloying elements. (This method will be referred to as the static method.)
  • the static method In this case, although the efficiency and the stability of nitrogen enrichment may be improved over the throw-in method, the reaction of the nitrogei/fenrichment with molten steel tends to take place violently, and dangerously, so tha-t a portion of the agent inevitably flows away and is lost. Therefore, the efficiency and the precision of nitrogen enrichment is far less than those of this invention, to say nothing about the incapability of the static method to attain a nitrogen content over a certain limit.
  • additives include elements that are commonly referred to as the norm-al alloying elements, such as nickel, chromium, molybdenum,
  • Those additives may conveniently be in a readily meltable form such as powder, granular, ribbon or tablet.
  • additives or nitrogen enrichment agents may be previously stored in the consumable transport pipe (the consumable container method), or they may be fed into the molten steel through the consumable transport pipe on stream of a suitable gas such as nitrogen, inert gas or non-'oxidizing gas (the gas-blow method).
  • a suitable gas such as nitrogen, inert gas or non-'oxidizing gas (the gas-blow method).
  • One factor rather critical in practicing this invention is to hold the relative depth of the free outlet of the consumable transport pipe at about 5 cm. to 75 cm. from the rising surface of the accumulating molten steel. This can be achieved by, for example, selecting the wall thickness and diameter of the pipe so that natural rate of its melting in the steel bath from the lower end is approximately the same as that of the rise of the molten steel surface. The required wall thickness and the diameter can be found by calculations, but one can readily determine a proper pipe -after a few experiments or trials.
  • FIGURE 1 is a schematic drawing of a ladle in vertical cross-section for practicing one embodiment of this invention
  • FIGURE 2 is la diagram to show the efficiency of nitrogen enrichment of molten steel due to this invention as compared with that due to a known method;
  • FIGURE 3 is a schematic drawing of a consumable transport pipe in vertical cross section that is convenient for slag reduction rening of the molten steel at the ladle;
  • FIGURE 4 is a schematic drawing of -a ladle in vertical cross-section for another embodiment of this invention.
  • FIGURE 1 illustrates schematically an exemplary large ladle equipped with a steel pipe for a convenient practicing of the gas-blow method of this invention, wherein 1 is the accumulating molten steel bath, 2 is the heat resistive lining of the ladle, 3 is the stopper, 4 is the hanger handle of the ladle, 5 is the consumable transport pipe whose consumed portion is indicated by broken line. Although in the gure, the consumable transport pipe 5 is fixed against the hanger handle of the ladle 4, this pipe may equally be well held by any other means, for example, by human hands.
  • FIGURE 2 shows the nitrogen yield in the product steel as function of the amount of nitrogen enrichment agent (calcium cyanamide) added per ton of molten steel. The solid line indicates the results due to my methods while the broken line represents those due to a known method.
  • nitrogen enrichment agent calcium cyanamide
  • Example 1 As soon as the tapping of steel into the ladle was commenced, an agricultural calcium cyanamide of thexcomposition listed in Table 1 l was blown into the melt on nitrogen gas under a pressure of about 1 to 1.5 kg./cm.2 according to the gas-blow method. As the tapping period was slightly over l minute for a 3 ton heat and slightly over 2 minutes for la l0 ton heat, the feeding rate of the calcium cyanamide was so adjusted that the desired quantity would be fed to the melt in slightly less than 1 minute or slightly less than 2 minutes in the respective cases.
  • the dimensions of the ladle were about 100 cm. in diameter at the upper opening and about 120 cm. deep for 3 ton heat about 115 cm. in diameter at the upper opening and about 160 cm. deep for 10 ton heat.
  • the diameter and the wall thickness of the consumable transport pipes used and other pertinent operational data are presented in the Table 2 under Charges 1, 2, 5 and 6. Actual measurements showed that the relative depth of the outlet end of the consumable transport pipes was in any one of the cases always about 20 cm. to 30 cm.
  • Example Z Electric arc furnace molten steels of 3 ton and 10 ton were treated by the consumable container method.
  • the same calcium cyanamide as the foregoing example was used for the nitrogen enrichment agent.
  • Granular aluminum (Charge 3) or aluminum, nickel, chromium, molybdenum, vanadium (Charge 4) or vanadium (Charge 7) were thoroughly admixed with the calcium cyanamide.
  • the mixture was then compactly stuffed into the consumable transport pipe of diameter and wall thickness as listed in the Table 2 under Charges 3, 4 and 7 until the apparent specific gravity of the calcium cyanamide became about 1.2 to 2.
  • the holding position of the pipe was the same as in FIGURE 1. Although both ends of the pipe were sealed in this example, it was found that the ends may be left open. Other factors such as the tapping time, the relative depth of the outlet and such were the same as in the Example 1.
  • the results from this example are summarized in Table 2 as Charges 3, 4 and 7, and in FIG- URE 2 by the double circles.
  • the pipe may be made in double structure or it may be encircled by a suitable material which is heat resistive enough at relatively lower temperatures but readily melts away at the temperature of the molten steel.
  • the present methods of nitrogen enrichment are superior to my other previous methods, the bath method and the interface method which are mentioned earlier, if the intrinsic difference in their respective applicability is disregarded. Namely, (l) since the nitrogen enrichment of the present methods is performed on the melt being tapped, entirely independent of the smelting process itself, the entire steelmaking duration suffers no prolongation whatsoever despite the #addition of this step; (2) the hardship that must be imposed upon the operator in handling the conduit pipe in front of hot furnace in the bath or interface method is entirely avoided in the present methods; (3) where the nitrogen yield on the agricultural calcium cyanamide is about 17.5% (oxidation slag) to about 21% (reduction slag) in the bath method or about 15% in the interface method, it is as high as about 32.6% in the present methods; (4) where the aluminum yield is about 25% when forcibly added into the melt at the ladle after having been enriched with nitrogen by either the bath or the interface method, it is as much as about 68.6% (gasblow method) or about 90.7% (
  • FIGUREl 3 Three consumable containers which are schematically ily lust'rated in FIGUREl 3.
  • FIGURE of linner ydiameter about 13 om.
  • A110 ton charge composedy mainly of scrap steel was melted in the same electric arcfurnace. as lin the .forel going examples andsrneltin the known method .of oxida- ⁇ reiining process by. applying the methods the yield of various ie- ⁇ tion refining by using pure oxygen gas; The hcatwas then tapped, without performing the. customary lreduction reintoaladle Athat was equipped with 4.5 cm.' whose ⁇ both ends .are closed, l'7 andlil are tbe ⁇ layers ofdeoxidizercalcium.
  • alloying element,- arrd 13 the .same 'manuel'. ias describedl .in lthe Example y2; (the consumable contair'ie'r.l method).
  • the .relative depthy of. the container outlet was always about to 30 cm., whie the other factors such as the dimensions of the ladle, the manner of container pipe holding, the time of tapping were all the same as those in the previous examples.
  • the time needed for the reduction refining process in this method is nothing more or less than the time needed for tapping, namely only about 2 minutes at most, whereas it is at least a few tens of minutes when performed at the furnace according to the normal way of smelting,
  • the yield of various additives is about 85% for silicon, about 92% for manganese, about 89% for aluminum in this method, whereas it is only about 63% for silicon, about 60% for manganese and about for aluminum in the customary method, (3) therefore, the ease and the accuracy of controlling the additives, and the economy of fuel or electric power associated with this method are evident.
  • a number of .pipes may in a ym'annerthat is shown schematically inl FIGURE 4 in y way' of: illustration.l In. FIGURE. 4;, 14 is theladle, l15 isy thelevel the molten steel: is expectedto attain ultimatelyl 16 is the consumable trans-y l17 is the consumable trans-y on. the; completion of tapping,
  • a method comprising adding a nitrogen enrichment agent to molten steel which is being tapped into a receptacle and which thereby has a continuously rising surface by supplying the agent to the molten steel by a consumable pipe which is placed in said steel and is consumed by the steel at a rate to supply said agent thereto at a lower discharge end of the pipe which continuously rises and remains at a depth of 5-75 cm. relative to said rising surface of the molten steel.
  • a method as claimed in claim 1 comprising enriching the steel up to about 0.040% nitrogen content.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Treatment Of Steel In Its Molten State (AREA)
US304019A 1962-08-24 1963-08-23 Method for adding additives to molten steel Expired - Lifetime US3322530A (en)

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JP37035065A JPS4917930B1 (enrdf_load_stackoverflow) 1962-08-24 1962-08-24

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JP (1) JPS4917930B1 (enrdf_load_stackoverflow)
AT (1) AT262355B (enrdf_load_stackoverflow)
GB (1) GB1041269A (enrdf_load_stackoverflow)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3784177A (en) * 1972-07-26 1974-01-08 Metallurg Exoproducts Corp Method and apparatus for ladle additions
US3934862A (en) * 1973-04-12 1976-01-27 Labate Michael D Device for supplying a treating agent to molten metal in a ladle
US3942775A (en) * 1973-04-02 1976-03-09 Labate Michael D Submerged desulphurization device and method
US4052202A (en) * 1975-09-25 1977-10-04 Reactive Metals & Alloys Corporation Zirconium alloy additive and method for making zirconium additions to steels
US4135920A (en) * 1976-07-06 1979-01-23 Barbakadze Dzhondo F Method of introducing powdered material into molten metal
US4211553A (en) * 1977-06-21 1980-07-08 Outokumpu Oy Method of refining of melts by means of a pulverous solid material and/or a gas
US4781887A (en) * 1986-11-14 1988-11-01 Nippon Steel Corporation Production of steels containing low melting point metals
EP0312068A1 (de) * 1987-10-15 1989-04-19 SKW Trostberg Aktiengesellschaft Verfahren zur Aufstickung von Gusseisen
EP0316920A1 (de) * 1987-11-19 1989-05-24 SKW Trostberg Aktiengesellschaft Stickstoffhaltiges Zusatzmittel für Stahlschmelzen
US20080314199A1 (en) * 2007-05-17 2008-12-25 Leslie Wade Niemi Enhanced Alloy Recovery In Molten Steel Baths Utilizing Cored Wires Doped With Deoxidants
US20080314201A1 (en) * 2007-05-17 2008-12-25 Marzec Gregory P Enhanced Alloy Recovery In Molten Steel Baths Utilizing Cored Wires Doped With Dispersants

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS534033U (enrdf_load_stackoverflow) * 1976-06-29 1978-01-14
JPS5390141U (enrdf_load_stackoverflow) * 1976-12-24 1978-07-24
FR2493873B1 (fr) * 1980-11-07 1986-03-28 Dunn Jr Edward Procede d'epuration de l'acier en poche de coulee

Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1335370A (en) * 1917-10-09 1920-03-30 Ellis Foster Co Desulfurizing cast-iron
US2085802A (en) * 1935-08-22 1937-07-06 Charles Hardy Inc Treatment of metals
US2370364A (en) * 1941-02-28 1945-02-27 Rustless Iron & Steel Corp Alloy steel process
US2662008A (en) * 1950-08-17 1953-12-08 United States Steel Corp Device for progressively releasing a reagent in a bath of molten metal
US2705196A (en) * 1952-02-20 1955-03-29 Manufacturers Chemical Corp Process for de-oxidizing a molten metal
US2747990A (en) * 1953-05-25 1956-05-29 British Cast Iron Res Ass Process of producing grey cast iron
GB785551A (en) * 1955-02-18 1957-10-30 Fredrik Jorgen Ording Hurum Method and apparatus for generating magnesium vapour in the interior of a molten metal or alloy using magnesium oxide
US2879156A (en) * 1956-06-07 1959-03-24 Hurum Fredrik Jorgen Ording Methods for the treatment of a melt with briquetted substances
US2915386A (en) * 1955-01-24 1959-12-01 Vanadium Corp Of America Device for supplying treating agents sequentially to molten metal
US2918365A (en) * 1953-08-10 1959-12-22 Yawata Seitetsu K K Method for controlling compositions of molten pig iron and slag in a blast furnace
GB874181A (en) * 1958-10-28 1961-08-02 Mannesmann Ag Method and apparatus for the addition of deoxidising and alloying elements to molten metal baths
US3056190A (en) * 1960-04-06 1962-10-02 Dow Chemical Co Composite metal article and method of making same
US3080228A (en) * 1960-08-03 1963-03-05 Blackstone Corp Process for the production of cast iron
US3208117A (en) * 1962-03-28 1965-09-28 Reisholz Stahl & Roehrenwerk Casting method

Patent Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1335370A (en) * 1917-10-09 1920-03-30 Ellis Foster Co Desulfurizing cast-iron
US2085802A (en) * 1935-08-22 1937-07-06 Charles Hardy Inc Treatment of metals
US2370364A (en) * 1941-02-28 1945-02-27 Rustless Iron & Steel Corp Alloy steel process
US2662008A (en) * 1950-08-17 1953-12-08 United States Steel Corp Device for progressively releasing a reagent in a bath of molten metal
US2705196A (en) * 1952-02-20 1955-03-29 Manufacturers Chemical Corp Process for de-oxidizing a molten metal
US2747990A (en) * 1953-05-25 1956-05-29 British Cast Iron Res Ass Process of producing grey cast iron
US2918365A (en) * 1953-08-10 1959-12-22 Yawata Seitetsu K K Method for controlling compositions of molten pig iron and slag in a blast furnace
US2915386A (en) * 1955-01-24 1959-12-01 Vanadium Corp Of America Device for supplying treating agents sequentially to molten metal
GB785551A (en) * 1955-02-18 1957-10-30 Fredrik Jorgen Ording Hurum Method and apparatus for generating magnesium vapour in the interior of a molten metal or alloy using magnesium oxide
US2879156A (en) * 1956-06-07 1959-03-24 Hurum Fredrik Jorgen Ording Methods for the treatment of a melt with briquetted substances
GB874181A (en) * 1958-10-28 1961-08-02 Mannesmann Ag Method and apparatus for the addition of deoxidising and alloying elements to molten metal baths
US3056190A (en) * 1960-04-06 1962-10-02 Dow Chemical Co Composite metal article and method of making same
US3080228A (en) * 1960-08-03 1963-03-05 Blackstone Corp Process for the production of cast iron
US3208117A (en) * 1962-03-28 1965-09-28 Reisholz Stahl & Roehrenwerk Casting method

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3784177A (en) * 1972-07-26 1974-01-08 Metallurg Exoproducts Corp Method and apparatus for ladle additions
US3942775A (en) * 1973-04-02 1976-03-09 Labate Michael D Submerged desulphurization device and method
US3934862A (en) * 1973-04-12 1976-01-27 Labate Michael D Device for supplying a treating agent to molten metal in a ladle
US4052202A (en) * 1975-09-25 1977-10-04 Reactive Metals & Alloys Corporation Zirconium alloy additive and method for making zirconium additions to steels
US4135920A (en) * 1976-07-06 1979-01-23 Barbakadze Dzhondo F Method of introducing powdered material into molten metal
US4211553A (en) * 1977-06-21 1980-07-08 Outokumpu Oy Method of refining of melts by means of a pulverous solid material and/or a gas
US4781887A (en) * 1986-11-14 1988-11-01 Nippon Steel Corporation Production of steels containing low melting point metals
EP0312068A1 (de) * 1987-10-15 1989-04-19 SKW Trostberg Aktiengesellschaft Verfahren zur Aufstickung von Gusseisen
US4970051A (en) * 1987-10-15 1990-11-13 Skw Trostberg Aktiengesellschaft Process for the introduction of nitrogen into cast iron
EP0316920A1 (de) * 1987-11-19 1989-05-24 SKW Trostberg Aktiengesellschaft Stickstoffhaltiges Zusatzmittel für Stahlschmelzen
US4897114A (en) * 1987-11-19 1990-01-30 Skw Trostberg Aktiengesellschaft Nitrogen-containing additive for steel melts
US20080314199A1 (en) * 2007-05-17 2008-12-25 Leslie Wade Niemi Enhanced Alloy Recovery In Molten Steel Baths Utilizing Cored Wires Doped With Deoxidants
US20080314201A1 (en) * 2007-05-17 2008-12-25 Marzec Gregory P Enhanced Alloy Recovery In Molten Steel Baths Utilizing Cored Wires Doped With Dispersants
DE112008001288T5 (de) 2007-05-17 2010-07-15 Affival, Inc. Verbesserte Legierungsrückgewinnung in Bädem aus geschmolzenem Stahl unter Verwendung mit Desoxidationsmitteln dotierter Fülldrähte

Also Published As

Publication number Publication date
AT262355B (de) 1968-06-10
JPS4917930B1 (enrdf_load_stackoverflow) 1974-05-07
GB1041269A (en) 1966-09-01

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