Classifications

• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
  • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
  • C21D9/54—Furnaces for treating strips or wire
  • C21D9/56—Continuous furnaces for strip or wire
  • C21D9/573—Continuous furnaces for strip or wire with cooling
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
  • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
  • C21D9/54—Furnaces for treating strips or wire
  • C21D9/64—Patenting furnaces
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
  • C21D1/62—Quenching devices
  • C21D1/667—Quenching devices for spray quenching
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
  • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
  • C21D9/54—Furnaces for treating strips or wire
  • C21D9/56—Continuous furnaces for strip or wire
  • C21D9/573—Continuous furnaces for strip or wire with cooling
  • C21D9/5732—Continuous furnaces for strip or wire with cooling of wires; of rods

Definitions

• the present invention relates to a method and a device for patenting at least one steel wire comprising
• This process offers the advantage that the contact between the coolant and the wire is direct, without the possibility of the formation of a vapor film around the wire, a film where the heat exchange is significantly less. favorable. Given the wire running speed combined with the flow speed of each curtain transverse to the wire running direction, the coolant does not have time to form a film of vapor around the wire and exchange Liquid thermal-steel wire remains excellent. Simultaneously the process offers the advantage of being able to stop the cooling at any desired temperature by a simple determination of the number of curtains necessary. This is particularly important in the case of patenting steel wires, where it is necessary to avoid too rapid quenching which gives rise to the appearance of martensite in the steel, which is to be avoided in most cases.
• the method comprises a projection from the bottom of said curtains in a turbulent upward flow.
• the coolant is sprayed under pressure like a continuous geyser and therefore very turbulent.
• the curtains with ascending turbulent flow have a vertex and the method further comprises, from said vertex and at least on one side of each curtain with ascending turbulent flow, a drop of turbulent flow liquid through which also scrolls said at least one steel wire.
• the wire can therefore pass through three successive streams of liquid with turbulent flow, one ascending and the other two descending, which makes the ensuing cooling very effective.
• the method comprises injecting pressurized gas bubbles into a mass of coolant, in an upwardly guided manner, and entraining said liquid by said bubbles in the form said curtains projected according to said upward turbulent flow.
• a mass of coolant Preferably use an inert gas with respect to steel, and in particular air.
• the air bubbles under pressure entrain the coolant and simultaneously make its flow turbulent, which promotes the desired direct heat exchange.
• the upward projection by air bubbles does not require an expensive energy expenditure and it makes it possible to avoid any pumping system for the coolant.
• the coolant can be any suitable liquid, water, liquid salt, a polymer, oil, and in particular water, because all the disadvantages encountered by the use of water in the prior art can be overcome by the process according to the invention.
• the process therefore takes the form of a simple process that is easy to control and adjust and allows consumption of only non-polluting and inexpensive materials, that is to say compressed air and cooling water.
• the present invention also relates to a device for implementing the method according to the invention.
• a device for implementing the method according to the invention.
• Such a device comprises - a furnace for austenitizing said at least one steel wire, - means for driving the said at least one steel wire to run, means for projecting at least one curtain of cooling liquid in which the latter has a turbulent flow oriented substantially transversely to said at least one running wire, in order to cool the latter in a liquid medium to said cooling temperature situated at below the austenitization temperature and above the martensitic transformation temperature, and
• this device also comprises
• the device comprises a tank containing the coolant which is arranged below said at least one running wire and means for projecting the curtains of said liquid in a turbulent upward flow. It is of course also possible to provide a tank arranged above the scrolling son and the fall or projection of curtains of coolant from the top.
• the temperature maintenance chamber is mounted so as to be able to move horizontally over the tank according to the number of curtains of liquid in service.
• FIG. 1 represents a view in longitudinal section of a device for cooling steel wires to be used in a patenting method according to the invention.
• FIG. 2 represents a plan view from above of FIG. 1.
• FIG. 3 represents a schematic view of an installation for the patenting of steel wires implementing the method according to the invention.
• FIGs 1 and 2 there is shown a tank 1 containing cooling water 2. Above this tank scrolls one or more steel wires 3 in a direction of travel indicated by the arrow 4, these wires preferably having a section with a diameter of less than 15 mm. Common scrolling drive means are represented schematically by the references 23 and 24.
• the water can be supplied by an inlet 5 and be discharged from above by an overflow 6. In the tank illustrated the height of water column is approximately 750mm H 2 O (7350 Pa).
• the overflow 6 can be in communication with a lower inlet 5 ′, by means of a heat exchanger not shown, so as to put the cooling water into circulation.
• the tank also includes means for projecting rising water curtains.
• projection means comprise air supply ducts 7 to 9 arranged at the bottom of the tank parallel to each other and transversely to the direction of travel of the wires.
• Each of these conduits is connected, through corresponding openings in the tank and by means of fittings 10 to 12, to a distributor duct 13 supplied with pressurized air by a fan 14.
• a shut-off valve 22 On each fitting 10 to 12 is provided a shut-off valve 22 which makes it possible to adjust the supply of pressurized air to the conduits 7 to 9 and to put them on or off as required.
• the air supply ducts 7 to 9 are perforated and therefore supply, in the tank water, air bubbles under pressure.
• two guide plates 15 and 16 are supported by the longitudinal walls 38 and 39 of the tank so as to pass through it from one side.
• the guide plates are not far apart and thus form a thin outlet slot.
• the guide plates 15 and 16 have a spacing clearly greater than that presented at their top. The guide plates thus form a kind of roof between the two sides of which the bubbles are forcedly guided upwards.
• the air bubbles entrain the water of the tank during their ascent and expel a curtain of turbulent water 17 upwards.
• a pressure of the order of 1000 mm of H 2 O (9806 Pa) for example the air bubbles entrain the water of the tank during their ascent and expel a curtain of turbulent water 17 upwards.
• the top of the water curtain it can be split in two and form two turbulent waterfalls 18 and 19 that the wire to be cooled must also pass through.
• the pairs of guide plates 15, 16 can be arranged sufficiently tightly in their succession so that the waterfalls of two neighboring curtains can cross. Of in this way, the wire runs continuously in water, and yet there is never the possibility of the formation of a film of water vapor around the wire.
• FIG 3 there is shown schematically an installation for patenting steel wires.
• This installation comprises, before the wires are cooled, a unit for heating the wires, for example as described in patent application WO01 / 73141.
• the heating unit consists of a fluidized bed oven 25 in which a web of wires 26 continuously scrolls in the direction of travel 27.
• the wires exit from this oven at an austenitization temperature, for example d 'about 950 ° C, and they then pass through a temperature equalization device 28 where the acquired wire temperature is maintained, in the case illustrated by recycling the burnt gases from the oven 25 through the conduit 29.
• the dissolution of carbides (cementite) is accomplished in this device 28 and the wires are then passed through the cooling device according to the invention 30.
• heating unit and the temperature maintenance device are not critical according to the invention and that they can be arranged in any suitable way to obtain a wire at the austenitization temperature.
• the cooling device 30, arranged for example as provided in Figures 1 and 2, allows the formation of several curtains of ascending water, turbulent, through which passes the sheet of son 26, without requiring deflection of the son. In the example illustrated, only 10 curtains were put into service while the tank allows the formation of 20.
• TTT curves transformation, temperature, time
• the wires are located opposite the nose of the S-curves, that is to say at a temperature corresponding to the minimum incubation time, to pass through these curves, which makes it possible to avoid disturbances that could influence the structure of the steel.
• a temperature holding chamber 31 is then provided for the wires which is capable of moving horizontally, for example as described in Belgian patent BE-A-838796.
• the chamber 31 is supported on a table 32 by rollers 33.
• Its inlet 34 is brought over the tank 30 and the sheet of wires, up to just behind the last curtain of water put into service, seen in the direction of scrolling wires.
• deflection rollers 35 and 36 the sheet of wires is deflected through the chamber 31 which, by electrical resistors 37 for example, is maintained at the temperature reached by the wires after passing through the last curtain of water, for example 580 ° C.
• the steel has preferably not yet reached the pearlitic transformation curves known as S. can then pass through them isothermally, possibly with a slight spontaneous rise in temperature at the start of processing, for example up to 600 ° C., and this out of contact with any coolant and without any intermediate cooling or reheating step in a gaseous medium.
• the rapid cooling obtained by the water curtains was stopped at the desired temperature, which is reached depending on the number of curtains put into service.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Mechanical Engineering (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Heat Treatment Of Strip Materials And Filament Materials (AREA)
• Heat Treatments In General, Especially Conveying And Cooling (AREA)

Applications Claiming Priority (3)

Publications (2)

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• 2002
  • 2002-06-06 BE BE2002/0372A patent/BE1014868A3/fr not_active IP Right Cessation
• 2003
  • 2003-06-05 AU AU2003232530A patent/AU2003232530A1/en not_active Abandoned
  • 2003-06-05 JP JP2004511559A patent/JP4851712B2/ja not_active Expired - Fee Related
  • 2003-06-05 CN CNB038130211A patent/CN100370038C/zh not_active Expired - Fee Related
  • 2003-06-05 CA CA2488156A patent/CA2488156C/fr not_active Expired - Fee Related
  • 2003-06-05 EP EP03756923A patent/EP1529122B1/de not_active Expired - Lifetime
  • 2003-06-05 US US10/516,595 patent/US7354493B2/en active Active
  • 2003-06-05 WO PCT/BE2003/000102 patent/WO2003104501A2/fr active Application Filing
  • 2003-06-05 AT AT03756923T patent/ATE554191T1/de active
  • 2003-06-05 KR KR1020047019694A patent/KR100941675B1/ko not_active IP Right Cessation

Non-Patent Citations (1)

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