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
  • C21C7/0056—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
  • 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
  • C21C7/005—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00 using exothermic reaction compositions

Definitions

• the invention relates to a method and means for simultaneous heating and cleaning of metal baths.
• furnace slags which interfere with the treatment. Removing the furnace slags is also time-consuming and requires equipment. Unfortunately, complete removal of furnace slag is not yet possible.
• US Pat. No. 4,518,422 teaches to load a correspondingly delimited bath volume with substances which are blown with gaseous oxygen within this volume, whereby on the one hand heat and on the other hand reactive slags of a certain composition arise, for example the known Perrin slag Aluminum base.
• the heat is to benefit the entire bathroom, it must be mixed. This is done with the help of an inert gas stream, which, however, has a cooling effect. Furthermore, a certain amount of heat is absorbed into the tube walls and thus removed from the bath.
• the object of the invention was to provide a method which allows a metal bath to be treated with cleaning furnaces and heated at the same time, the heating effect being brought about by a metallothermal reaction and a maximum amount of heat being transferred to the bath.
• cored wire consisting of a steel sheath and a filling such as calcium / silicon / lime, magnesium / calcium fluoride, ferrosilicon and the like. has long been common in ladle metallurgy.
• the advantage of the cored wire is that it can be easily metered by simply specifying a certain length of wire.
• the basic idea of the invention is that it must be advantageous to allow an exothermic reaction to take place deep in the bath instead of initiating it in accordance with the prior art on a surface zone which has been freed from slags by cumbersome precautions, with some of the heat generated being lost goes and the reaction products must be distributed in the bathroom by inert gas flushing.
• any suitable oxide such as Fe203 can serve as an oxygen supplier.
• the metallic oxygen acceptor preferably aluminum, in this case has to do reduction work which requires heat. It is therefore more advantageous to use peroxides as oxygen suppliers, for example calcium peroxide, which releases the oxygen relatively easily at about 290 ° C.
• the filling is diluted, preferably with lime or with a mixture of lime / river paste.
• the purpose of this dilution is also to prevent or at least weaken the formation of inclusions by the diluent floating away upwards.
• an inert gas flushing can be carried out, whereby the gas throughputs, according to the above, may only be weak (about 0.05 - 0.1 Nm3 / t.minute).
• the cored wire consisted of a mixture of 25.07 wt .-% aluminum and 74.93 wt .-% of Fe203 with a residual proportion of gait in the order of 2%.
• the cored wire was iron-coated and had a diameter of 13 mm.
• the steel temperature in the bath was 1,577 ° C. and the oxygen content was 30.3 ppm.
• the liquid steel was homogenized with 2 Nm3 / h argon by injecting the floor over the floor purging stones during the entire winding time.
• the bath temperature could be kept at 1,576 ° C. over the course of the 15-minute cored wire winding.
• the thermal efficiency based on the aluminum in the wire winding all in, was 82.9%.
• the oxygen content of the melt was 1.6 ppm.
• a positive effect on the inclusion content could be achieved by winding the wire into the steel bath and by swirling the Perrin-like slag caused by argon blown into the bottom.
• Ferro-Nb, Ferro-Si and Ferro-Mn alloys were added at the end of the test; the steel was then cast at a temperature of 1,560 ° C.

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)

Applications Claiming Priority (2)

Publications (1)

Family

ID=19730753

Family Applications (1)

Country Status (5)

Cited By (3)

Families Citing this family (6)

Citations (8)

Family Cites Families (1)

• 1986
  • 1986-08-11 LU LU86552A patent/LU86552A1/de unknown
• 1987
  • 1987-07-31 EP EP87111094A patent/EP0263255A1/fr not_active Withdrawn
  • 1987-08-04 AU AU76552/87A patent/AU7655287A/en not_active Abandoned
  • 1987-08-06 US US07/082,833 patent/US4773929A/en not_active Expired - Fee Related
  • 1987-08-11 JP JP62200723A patent/JPS6347329A/ja active Pending

Patent Citations (9)

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