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
  • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
  • C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
• • 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
  • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
  • C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
  • C21D8/065—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires of ferrous alloys
• • 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
  • C21D9/525—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length for wire, for rods
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
• • 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
  • C21D2211/00—Microstructure comprising significant phases
  • C21D2211/001—Austenite
• • 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
  • C21D2211/00—Microstructure comprising significant phases
  • C21D2211/008—Martensite
• • 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
  • Y10T428/12354—Nonplanar, uniform-thickness material having symmetrical channel shape or reverse fold [e.g., making acute angle, 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
  • Y10T428/12375—All metal or with adjacent metals having member which crosses the plane of another member [e.g., T or X cross section, 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
  • Y10T428/12431—Foil or filament smaller than 6 mils

Definitions

• the invention relates to ready-to-use metal wires and methods for obtaining these wires.
• These ready-to-use threads are used, for example, to reinforce plastic or rubber articles, in particular pipes, belts, plies, tire casings.
• ready-to-use wire means, in a manner known in the art, that this wire can be used, for the intended application, without subjecting it to a heat treatment liable to modify its structure. metallurgical and without subjecting it to a deformation of its metallic material, for example a wire drawing, capable of modifying its diameter.
• Patent application WO-A-92/14811 describes a process for obtaining a ready-to-use wire comprising a steel substrate, the structure of which comprises more than 90% of hammered quenched martensite, the steel having a carbon content at less equal to 0.05% and at most equal to 0.6%, this substrate being coated with a metal alloy other than steel, for example brass.
• the process for obtaining this wire comprises a quenching treatment on a work hardened wire by heating the wire above the transformation point AC3 to give it a homogeneous austenite structure and then cooling it quickly, at a speed at least equal to 150 ° C / second, below the end point of martensitic transformation.
• the diffusion treatment is carried out at the same time as the income of the wire, which limits the manufacturing costs.
• tempering temperature necessary to obtain good diffusion of the coating does not always correspond precisely to that necessary to obtain sufficient resistance before drawing.
• the invention relates to a ready-to-use metal wire, this wire having the following characteristics:
• a) it comprises a microalloyed steel having a carbon content at least equal to 0.2% by weight and at most equal to 0.6% by weight; this steel also comprises at least one alloying element chosen from the group formed by vanadium, molybdenum and chromium, the steel comprising at least 0.08% and at most 0.5% by weight of the element alloy or all alloy elements;
• this steel has a structure consisting almost entirely of hardened returned martensite
• the diameter of the wire is at least equal to 0.10 mm and at most equal to 0.50 mm; d) the breaking strength of the wire is at least equal to 2800 Mpa.
• the ready-to-use wire comprises a coating of a metal alloy other than steel placed on a microalloyed steel substrate having the above-mentioned characteristics.
• this steel has a carbon content at least equal to 0.2% by weight and at most equal to 0.6% by weight; this steel also comprises at least one alloying element chosen from the group formed by vanadium, molybdenum and chromium, the steel comprising at least 0.08% and at most 0.5% by weight of the element alloy or all alloy elements;
• this wire rod is deformed so that the wire diameter after this deformation is less than 3 mm;
• the wire is then cooled to a temperature below 250 ° C;
• a deposit is made on the wire of at least two metals capable of forming by diffusion an alloy, the aforementioned microalloyed steel thus serving as a substrate and, during step d ) previously defined, heating to the tempering temperature also serves to cause the formation, by diffusion, of an alloy of these metals, for example brass.
• the invention also relates to assemblies comprising at least one ready-to-use wire according to the invention.
• assemblies are, for example, strands, wire cables, in particular cables with layers of wires or cables made up of strands of wires.
• the invention also relates to articles reinforced at least in part by ready-to-use wires or by assemblies in accordance with the preceding definitions, such articles being, for example, hoses, belts, plies, tire casings.
• structure consisting almost entirely of returned martensite means that this structure contains less than 1% of non-martensitic phase (s). this other phase, or these other phases, being due to inevitable heterogeneities of the steel.
• breaking strength measurements are carried out in tension according to the method described in the French standard AFNOR NF A 03-151 of June 1978.
• the structure of the steels is determined visually with an optical microscope with a magnification of 400.
• the preparation of the samples by chemical attack as well as the examination of the structures are carried out in accordance with the following reference: De Ferri Metallographica vol. No. II, A. Schrader, A. Rose, Edition Verlay Stahleisen GmbH. D ⁇ sseldorf.
• the martensitic transformation end point M F is determined in accordance with the following reference: Ferrous Physical Metallurgy, A. Kumar Sinha, Edition Butterworths 1989. The relation is used for this purpose
• M s 539 - 423.C - 30.4.Mn - 17.7.Ni - 12, l .Cr - 7.5.Mo - 7.5.Si + lO.Co.
• C. Mn, Ni, Cr, Mo. Si and Co represent the% by weight, that is to say the% by weight, of the chemical bodies of which they are the symbols.
• vanadium can be used in this formula having the same effect as molybdenum, while the aforementioned reference does not mention vanadium. 5. Vickers hardness
• the diffusion rate T d is given by the formula
• T d [area of peak ⁇ ] / [area of peak ⁇ + area of peak ⁇ ]
• the peak ⁇ corresponds approximately to the angle of 50 ° and the peak ⁇ corresponds approximately to the angle 51 °.
• the steel of these machine wires has a pearlitic structure.
• wires A and B are therefore identical and not micro-alloyed, the wires C and D being micro-alloyed and different from each other.
• the quench cooling conditions are as follows.
• Wires A, C and D speed of 130 ° C / second using as quench gas a mixture of hydrogen and nitrogen (75% by volume of hydrogen, 25% by volume of nitrogen).
• Wire B speed of 180 ° C / second using pure hydrogen.
• the Vickers hardness is measured on each of the wires obtained referenced Al. Bl, Cl and Dl, the letters A, B, C and D each identifying the aforementioned starting machine wire. The values obtained are shown in Table 3.
• the Al wire is unusable due to its too low hardness, which is due to the fact that its structure is not made up solely of martensite but contains both martensite and bainite.
• the wires B l, Cl and D l each consist almost entirely of martensite and their Vickers hardness is satisfactory.
• the wires C l and Dl made of microalloyed steel, are obtained with an easy to carry out quenching (relatively low speed, with an inexpensive and non-dangerous gas mixture), while the wire B 1 is obtained with a difficult and expensive process ( high quenching speed, using pure hydrogen), this process making it possible to obtain sufficient hardness but which is however lower than that of the microalloyed wires C l and Dl.
• vanadium makes it possible to improve the hardenability of the steel, that is to say the formation of a single martensite phase during quenching.
• the total amount of the two metals deposited is 390 mg per 100 g of each of the wires, with 64% by weight of copper and 36% by weight of zinc.
• the three wires B2, C2 and D2 are thus obtained.
• control wire B2 is then heated by the Joule effect, for 5 seconds each time, to three tempering temperatures T r (525 ° C, 590 ° C, 670 ° C) and then cooled to room temperature (about 20 ° C) , in order to evaluate the effect of this heat treatment on the tensile strength R m and on the diffusion rate T d of the brass, formed by the alloy of copper and zinc, for the wire thus obtained B3, in each case.
• the diffusion rate T d is insufficient (less than 0.85) but that the breaking strength is higher than for the other temperatures.
• a very good diffusion of the brass is obtained for the treatment at 670 ° C (diffusion greater than 0.85) but the resistance to rupture is notably lower than at 525 ° C and is not sufficient to allow obtaining high tensile strength by subsequent drawing.
• the breaking strength is slightly higher for treatment at 590 ° C than that obtained at 670 ° C, with a slightly lower diffusion of the brass, although satisfactory, but this resistance is also insufficient to guarantee a high resistance after wire drawing. .
• the diffusion rate of the brass is greater than 0.9, that is to say that the diffusion is very good, and that the breaking strength is also very good, very superior to that obtained for the control wire B3 when the diffusion of the brass is greater than 0.9.
• the presence of vanadium therefore makes it possible, unexpectedly, to have both a good diffusion of the brass and a good breaking strength thanks to the formation of fine precipitates of carbonitride and / or vanadium carbide, which was in solution after the quenching period, despite the very short income time.
• vanadium precipitates in steels for very long tempering times ranging from about ten minutes to several hours, but it is surprising to find such precipitation for such short times, less than a minute, for example less than 10 seconds.
• T r are those indicated previously for the income and the values of T d are those indicated previously and which were determined after the brass plating operation, before drawing, the values of T d being practically unchanged during the wire drawing.
• wires C4 and D4 in accordance with the invention are characterized both by a good diffusion rate of the brass (greater than 0.9) and by an excellent resistance at rupture (greater than 2900 MPa).
• the control wires B4 have values of tensile strength significantly lower than that of the wires C4 and D4 in accordance with the invention, except for the wire B4 initially treated at a tempering temperature of 525 ° C., but then the diffusion rate brass is insufficient (less than 0.85), that is to say that the drawing is difficult to carry out and leads to frequent breaks of the wire during its deformation, which makes obtaining the wire much more difficult than in the case of wires C4 and D4 of the invention.
• the wire rod usable for the invention is produced in the manner which is usual for a wire rod intended to be transformed into fine wire ready for use to reinforce the casings of tires.
• This steel is first produced in an electric oven or an oxygen converter, then deoxidized in a ladle using an oxidant, such as silicon, which does not risk producing alumina inclusions.
• the vanadium is then introduced into the bag in the form of loose pieces of ferrovanadium by addition to the metal bath.
• the process is similar if the alloying element is to be chromium or molybdenum.
• the steel bath is poured continuously in the form of billets or blooms.
• These semi-finished products are then conventionally rolled into machine wire with a diameter of 5.5 mm, first into billets, if it is blooms, or directly into machine wire if it is a billet. .
• the carbon content of the steel is at least equal to 0.3% and at most equal to 0.5% (% by weight), this content being for example approximately 0.4%;
• the alloying element or all of the alloying elements represents at most 0.3% by weight of the steel
• the breaking strength is at least equal to 2900 MPa
• the diameter is at least equal to 0.15 mm and at most equal to 0.40 mm.
• one has at least one of the following characteristics for the process according to the invention:
• the carbon content of the steel of the wire rod used is at least equal to 0.3% and at most equal to 0.5% (% by weight), this content being for example approximately 0.4%;
• the alloying element or all of the alloying elements of the steel of the wire rod used represents at most 0.3% by weight of this steel
• the cooling rate during quenching is less than 150 ° C / second;
• the tempering temperature is at least equal to 400 ° C and at most equal to 650 ° C;
• the wire is cooled to room temperature after having brought it to tempering temperature
• the rate of deformation ⁇ after the tempering treatment is at least equal to 3.
• the alloying element is vanadium alone, which has the advantage of giving small precipitates, while chromium gives large precipitates and that molybdenum tends to cause segregation. If chromium is used alone, its content in the steel is advantageously at least equal to 0.2%.
• the deformation of the wire in the previous examples was carried out by drawing, but other techniques are possible, for example rolling, possibly associated with drawing, for at least one of the deformation operations.
• the coating of the ready-to-use wire according to the invention is an alloy other than brass, this alloy being obtained with two metals, or more than two metals, for example ternary copper - zinc - nickel, copper - zinc - cobalt, copper - zinc - tin alloys, the main thing being that the metals used are capable of forming an alloy, by diffusion, at a temperature at most equal to the annealing temperature.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Manufacturing & Machinery (AREA)
• Heat Treatment Of Strip Materials And Filament Materials (AREA)
• Heat Treatment Of Steel (AREA)

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• 1996
  • 1996-01-16 FR FR9600406A patent/FR2743573A1/fr active Pending
• 1997
  • 1997-01-08 AU AU13834/97A patent/AU1383497A/en not_active Abandoned
  • 1997-01-08 US US09/101,652 patent/US6106637A/en not_active Expired - Lifetime
  • 1997-01-08 JP JP9525726A patent/JP2000503724A/ja active Pending
  • 1997-01-08 DE DE69703149T patent/DE69703149T2/de not_active Expired - Lifetime
  • 1997-01-08 RU RU98115314/02A patent/RU2177510C2/ru not_active IP Right Cessation
  • 1997-01-08 ES ES97900245T patent/ES2150752T3/es not_active Expired - Lifetime
  • 1997-01-08 WO PCT/FR1997/000028 patent/WO1997026379A1/fr not_active Application Discontinuation
  • 1997-01-08 BR BR9706987A patent/BR9706987A/pt not_active IP Right Cessation
  • 1997-01-08 KR KR1019980705397A patent/KR19990077252A/ko not_active Application Discontinuation
  • 1997-01-08 CN CN97193103A patent/CN1079117C/zh not_active Expired - Fee Related
  • 1997-01-08 EP EP97900245A patent/EP0877824B1/de not_active Expired - Lifetime
  • 1997-01-08 CA CA002243324A patent/CA2243324A1/fr not_active Abandoned

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