Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/0007—Reinforcements made of metallic elements, e.g. cords, yarns, filaments or fibres made from metal
• • 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
  • C21D7/00—Modifying the physical properties of iron or steel by deformation
  • C21D7/02—Modifying the physical properties of iron or steel by deformation by cold working
  • C21D7/10—Modifying the physical properties of iron or steel by deformation by cold working of the whole cross-section, e.g. of concrete reinforcing bars
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B15/00—Layered products comprising a layer of metal
  • B32B15/04—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B15/06—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material of natural rubber or synthetic rubber
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B15/00—Layered products comprising a layer of metal
  • B32B15/18—Layered products comprising a layer of metal comprising iron or steel
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B15/00—Layered products comprising a layer of metal
  • B32B15/20—Layered products comprising a layer of metal comprising aluminium or copper
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B25/00—Layered products comprising a layer of natural or synthetic rubber
  • B32B25/02—Layered products comprising a layer of natural or synthetic rubber with fibres or particles being present as additives in the layer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B25/00—Layered products comprising a layer of natural or synthetic rubber
  • B32B25/12—Layered products comprising a layer of natural or synthetic rubber comprising natural rubber
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B25/00—Layered products comprising a layer of natural or synthetic rubber
  • B32B25/16—Layered products comprising a layer of natural or synthetic rubber comprising polydienes homopolymers or poly-halodienes homopolymers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B3/00—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar form; Layered products having particular features of form
  • B32B3/02—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar form; Layered products having particular features of form characterised by features of form at particular places, e.g. in edge regions
  • B32B3/04—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar form; Layered products having particular features of form characterised by features of form at particular places, e.g. in edge regions characterised by at least one layer folded at the edge, e.g. over another layer ; characterised by at least one layer enveloping or enclosing a material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B3/00—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar form; Layered products having particular features of form
  • B32B3/10—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar form; Layered products having particular features of form characterised by a discontinuous layer, i.e. formed of separate pieces of material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/04—Interconnection of layers
  • B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
• • 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
  • C21D9/34—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for tyres; for rims
• • 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
  • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
• • 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
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C1/00—Making non-ferrous alloys
  • C22C1/02—Making non-ferrous alloys by melting
• • 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
  • C22C38/004—Very low carbon steels, i.e. having a carbon content of less than 0,01%
• • 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
  • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
• • 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
  • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
• • 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
  • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
• • 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
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B1/00—Constructional features of ropes or cables
  • D07B1/06—Ropes or cables built-up from metal wires, e.g. of section wires around a hemp core
  • D07B1/0606—Reinforcing cords for rubber or plastic articles
  • D07B1/066—Reinforcing cords for rubber or plastic articles the wires being made from special alloy or special steel composition
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2250/00—Layers arrangement
  • B32B2250/03—3 layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2250/00—Layers arrangement
  • B32B2250/40—Symmetrical or sandwich layers, e.g. ABA, ABCBA, ABCCBA
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2255/00—Coating on the layer surface
  • B32B2255/06—Coating on the layer surface on metal layer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2255/00—Coating on the layer surface
  • B32B2255/20—Inorganic coating
  • B32B2255/205—Metallic coating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2264/00—Composition or properties of particles which form a particulate layer or are present as additives
  • B32B2264/10—Inorganic particles
  • B32B2264/101—Glass
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2264/00—Composition or properties of particles which form a particulate layer or are present as additives
  • B32B2264/10—Inorganic particles
  • B32B2264/107—Ceramic
  • B32B2264/108—Carbon, e.g. graphite particles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
  • B32B2307/54—Yield strength; Tensile strength
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
  • B32B2307/552—Fatigue strength
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/714—Inert, i.e. inert to chemical degradation, corrosion
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
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• • B—PERFORMING OPERATIONS; TRANSPORTING
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  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
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• • B—PERFORMING OPERATIONS; TRANSPORTING
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  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2605/00—Vehicles
  • B32B2605/18—Aircraft
• • 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
  • C21D2211/005—Ferrite
• • 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
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2001—Wires or filaments
  • D07B2201/2002—Wires or filaments characterised by their cross-sectional shape
  • D07B2201/2003—Wires or filaments characterised by their cross-sectional shape flat
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2001—Wires or filaments
  • D07B2201/201—Wires or filaments characterised by a coating
  • D07B2201/2011—Wires or filaments characterised by a coating comprising metals
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2205/00—Rope or cable materials
  • D07B2205/30—Inorganic materials
  • D07B2205/3021—Metals
  • D07B2205/3025—Steel
  • D07B2205/3039—Martensite
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
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  • D07B2205/30—Inorganic materials
  • D07B2205/3021—Metals
  • D07B2205/3025—Steel
  • D07B2205/3042—Ferrite
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
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  • D07B2205/30—Inorganic materials
  • D07B2205/3021—Metals
  • D07B2205/3025—Steel
  • D07B2205/3046—Steel characterised by the carbon content
  • D07B2205/305—Steel characterised by the carbon content having a low carbon content, e.g. below 0,5 percent respectively NT wires

Definitions

• the present invention relates to motor vehicle tires, as well as to metal reinforcements used for reinforcing such tires.
• a tire with a radial carcass reinforcement for a vehicle for example of the touring, light truck or heavy vehicle type, to mention only these examples, comprises, it is known, a tread, two inextensible beads intended to be in contact with a mounting rim. , two flexible flanks reinforced by the carcass reinforcement, connecting the beads to the tread and a rigid crown reinforcement or "belt” arranged circumferentially between the carcass reinforcement and the tread, this belt consisting of various plies (or “layers") of rubber reinforced or not by reinforcing elements (or “reinforcements”) such as cords or monofllaments, metal or textile type.
• the belt of a tire is generally composed of at least two superimposed belt plies, sometimes called “working plies” or “crossed plies”, whose reinforcing cables, generally metallic, are arranged substantially parallel to each other. to each other within a web, but crossed from one web to another, that is to say inclined, symmetrically or otherwise, with respect to the median circumferential plane, of an angle which is generally between 10 ° and 45 ° depending on the type of tire.
• a tire belt must satisfy, in known manner, different, often contradictory, requirements, namely: to be as rigid as possible at low deformation, since it contributes in a substantial way to stiffening the top of the tire;
• the third and fourth requirements are particularly strong, for example for truck tire shells, designed to be retreaded one or more times when the treads they comprise reach a degree of critical wear after prolonged rolling.
• the object of the present invention is a new tire, reinforced by a carbon steel metal strip with a specific microstructure and high mechanical properties, said tire having, thanks to this ribbon, a substantially improved endurance, particularly with regard to the problem of belt cleavage, compared to the tires reinforced by carbon steel ribbons known from the prior art.
• This specific tape also provides the tire of the invention with improved resistance to corrosion fatigue.
• the present invention relates to a tire for a motor vehicle comprising at least one ribbon made of carbon steel with a very low carbon content and high strength in the hardened state, characterized by the following points: carbon a (% by weight) between 0.05% and 0.4% of carbon, between 0.5% and 4% of manganese, between 0.1% and 2.5% of silicon, optionally ) less than 1, 5%) of aluminum, (ii) less than 0.5%> of each of the metals boron, chromium, cobalt, copper, molybdenum, nickel, niobium, titanium, tungsten, vanadium, zirconium, and (iii) less than 0,05%> of each of the elements phosphorus, sulfur, nitrogen, or rare earth, the remainder consisting of iron and unavoidable impurities resulting from the elaboration; the microstructure of hardened carbon steel is mainly martensitic or ferritic-martensitic; the resistance noted Rm ribbon is greater than 1
• the above ribbon with a specific microstructure, has for remarkable properties a high mechanical strength, despite a very low carbon content, all combined with improved resistance to corrosion and fatigue-corrosion mechanisms.
• the invention relates to tires both in the raw state (that is to say before cooking or vulcanization of the rubber) and in the cooked state (after baking the rubber).
• the tires of the invention may be intended in particular for motor vehicles of the tourism, 4x4, "SUV” (Sport Utility Vehicles) type, but also for industrial vehicles chosen from light trucks, "heavy trucks” - ie, metro , buses, road transport vehicles (trucks, tractors, trailers), off-the-road vehicles -, agricultural or civil engineering machinery, aircraft, other commercial vehicles for transport or handling.
• FIGS. 1 to 4 relating to these examples which schematize or reproduce: in cross-section, an example of a composite (metal / rubber) usable as reinforcing structure in the tire according to the invention (Fig. 1);
• FIG. 3 an optical microscope view of a ferritic-martensitic microstructure observed on a low-carbon steel strip of the two-phase type capable of reinforcing the tire of the invention, before (FIG 3) and after work-hardening (FIG. ) of this carbon steel.
• rubber or "elastomer” (both terms being considered synonymous): any type of elastomer, whether of the diene type or of the non-diene type, for example thermoplastic;
• rubber composition or “rubber composition” means a composition which comprises at least one rubber and a filler
• layer means a sheet, strip or other element of relatively small thickness in relation to its other dimensions, preferably having the ratio of the thickness to the most other dimensions is less than 0.5, more preferably less than 0.1
• axial direction means a direction substantially parallel to the axis of rotation of the tire
• circumferential direction means a direction that is substantially perpendicular both to the axial direction and to a radius of the tire (in other words, tangent to a circle whose center is on the axis of rotation of the tire);
• radial direction means a direction along a radius of the tire, that is to say any direction passing through the axis of rotation of the tire and substantially perpendicular to that direction, that is to say with a perpendicular at this direction an angle not diverging by more than 5 degrees;
• oriented perpendicular to an axis or direction speaking of any element such as a reinforcement, an element that is oriented substantially perpendicular to that axis or direction, that is to say, with a perpendicular at that axis or direction an angle not diverging by more than 5 degrees;
• M “median circumferential plane” (denoted by M): the plane perpendicular to the Y axis of rotation of the tire which is located halfway between the two beads and passes through the middle of the crown reinforcement or belt;
• x and / or y means “x” or “y” or both (i.e., “x and y”). Any range of values designated by the expression “between a and b” represents the range of values from more than “a” to less than “b” (i.e., “a” and “b” terminals excluded ) while any range of values referred to as “a to b” means the range of values from “a” to "b” (ie including the strict “a” and “a” limits). "B”).
• the present invention therefore relates to a tire comprising, as a metal reinforcement, a steel strip with a very low carbon content, precisely between 0.05% and 0.4% of carbon, also comprising between 0.5% and 4%> manganese, between 0.1%> and 2.5%> of silicon, optionally (i) less than 1.5% of aluminum, (ii) less than 0.5% of each of the boron metals, chromium, cobalt, copper, molybdenum, nickel, niobium, titanium, tungsten, vanadium, zirconium, and (iii) less than 0.05% of each of the elements phosphorus, sulfur, nitrogen, or rare earth, the rest being made of iron and unavoidable impurities resulting from the elaboration.
• the ribbon is made of steel, that is to say that by definition it is mainly (for more than 50%) by mass) or completely (for 100% by weight) of steel.
• the steel is advantageously as defined in standard NF EN 10020 (September 2000). According to this standard, a steel is a material containing more iron than any other element and whose carbon content is less than 2%. Still in accordance with this standard, the steel optionally includes other alloying elements.
• the carbon content of the carbon steel is in a range from 0.1 to 0.3%, more preferably in a range from 0.15% to 0.25%.
• its manganese content is in a range of 1% to 3%, more preferably in a range of 1.5% to 2.5%.
• its silicon content is between 0.1 and 1.5%, more preferably in a range of 0.2% to 1.0%, in particular in a range of 0.3% to 0%. , 8%.
• Its optional aluminum content is preferably less than 1.0%, more preferably less than 0.5%.
• the level of each of the optional metals boron, chromium, cobalt, copper, molybdenum, nickel, niobium, titanium, tungsten, vanadium, zirconium is less than 0.3%, more preferably less than 0.2%.
• the level of each of the phosphorus and sulfur elements is preferably less than 0.020%, more preferably less than 0.015%.
• the microstructure of the carbon steel in the hardened state is mainly martensitic or mainly ferritomersitic, that is to say that it constitutes more than 50% by volume either martensite phases (in this case, called “mainly martensitic”), or phases of martensite and ferrite (in this case, called “mainly ferrito -martensitic”).
• a martensitic or ferrito- martensitic microstructure has, in known manner, martensite slats or martensite slats, respectively, combined with ferrite phases.
• the volume percentage of martensite is more preferably greater than 90%, in particular greater than 95%.
• the total volume percentage of martensite and ferrite is more preferably greater than 90%, in particular greater than at 95%. More preferably still, for such a microstructure, the ferrite content itself is greater than 60%.
• This volume ratio is determined in a known manner by image analysis, by simply measuring the area occupied by the martensitic, or martensitic and ferritic phases and relating them to the total surface of the image.
• the carbon steel is a type of steel "TRIP” (TRans Formation Induced Plasticity) or “T” (steel plasticity induced by Transformation); In the sense of the NF EN 10338 standard (October 2015), this is a reminder of a mainly ferritic matrix steel containing residual austenite capable of transforming into martensite during the forming process.
• the carbon steel is a steel of the "two-phase” type, also called “Dual Phase”; in the sense of standard NF EN 10338 (October 2015) above, it is a steel containing mainly ferrite and martensite and possibly bainite as a complementary phase.
• the carbon steel is a martensitic type steel ("MS"); according to standard NF EN 10338 (October 2015), it is a martensitic matrix steel containing small amounts of ferrite and / or bainite.
• cold-rolled strip in English “cold-rolled” strip
• Another essential feature of the carbon steel ribbon suitable for the tire of the invention is that it has a very high tensile strength in the hardened state, making it suitable in the form of ribbon for reinforcing tires. for motor vehicles.
• Its mechanical resistance Rm is preferably greater than 1500 MPa, more preferably greater than 1800 MPa, even more preferably greater than 1900 MPa.
• Its total elongation at break At is preferably between 1% and 3%, more preferably within a range of 1.5 to 2.5%.
• the maximum breaking stress or rupture limit Rm corresponds to the force required to break the wire in traction; the measurements of Rm (in MPa) and At (in% of initial length before traction) are carried out according to ISO 6892 of 1984, at ambient temperature (23 ° C).
• the thickness denoted "Ts" of the ribbon is preferably less than 2 mm, more preferably less than 1 mm. More preferably still, this thickness Ts is between 0.1 and 0.8 mm, in particular in a range of 0.15 to 0.5 mm, more particularly in a range of 0.2 to 0.5 mm, more particularly in a range of 0.25 to 0.45 mm or in a range of 0.15 to 0.35 mm.
• the width denoted "Ws" of this ribbon is conventionally less than 50 mm, preferably less than 20 mm. More preferably still, this width Ws is between 1 and 15 mm, more preferably greater than 1 mm and less than or equal to 10 mm, more particularly within a range of 2.5 to 10 mm, more preferably still 2.5. at 5 mm.
• the ribbon may be coated with a metal layer improving for example its properties of use, such as adhesion properties, corrosion resistance or resistance to aging.
• the tape is coated with a layer of zinc or more preferably with a layer of brass (copper and zinc alloy), deposited for example electrolytically from brass anodes.
• the brass coating preferably has a very small thickness, substantially less than one micrometer, for example of the order of 0.10 to 0.30 ⁇ , which is negligible compared to the thickness of the tape.
• the ribbon could be covered with a metal layer other than brass or zinc, for example having the function of improving the corrosion resistance and / or adhesion to rubber, for example a thin layer of Co , Ni, Al, an alloy of two or more compounds Cu, Zn, Al, Ni, Co, Sn.
• the ribbon may also be devoid of any metal coating, that is to say so-called "clear" steel.
• the ribbon described above is typically incorporated with rubber to form a metal / rubber composite (10) having at least one such ribbon (12), preferably several of them aligned in parallel.
• the total thickness of the composite denoted "Te” can vary widely depending on the particular applications targeted; it is preferably between 0.5 and 3.0 mm, more preferably between 0.5 and 1.5 mm.
• this composite has a width "Wc" (in the Y direction) and a length (in the X direction) which are respectively greater than 2.5 mm and 10 cm, more preferably greater than 5 mm and 20 cm respectively.
• Each constituent rubber composition of the composite is based on at least one elastomer, preferably of the diene type.
• elastomer elastomer alone or elastomer mixture
• diene monomers that is to say monomers carrying two carbon-carbon double bonds, whether the latter are conjugated or not.
• This diene elastomer is preferably chosen from the group consisting of polybutadienes (BR), natural rubber (NR), synthetic polyisoprenes (IR), various butadiene copolymers, the various isoprene copolymers, and mixtures of these elastomers, such copolymers being chosen in particular from the group consisting of butadiene-styrene copolymers (SBR), isoprene-butadiene copolymers (BIR), isoprene-styrene copolymers (SIR) and copolymers of isoprene-butadiene-styrene (SBIR).
• SBR butadiene-styrene copolymers
• BIR isoprene-butadiene copolymers
• SIR isoprene-styrene copolymers
• SBIR copolymers of isoprene-butadiene-styrene
• a particularly preferred embodiment consists of using an "isoprene" elastomer, that is to say a homopolymer or copolymer of isoprene, in other words a diene elastomer chosen from the group consisting of natural rubber (NR ), the synthetic polyisoprenes (IR), the various isoprene copolymers and the mixtures of these elastomers.
• the isoprene elastomer is preferably natural rubber or synthetic polyisoprene of the cis-1,4 type.
• polyisoprenes having a content (mol%) of cis-1,4 bonds greater than 90%, more preferably still greater than 98%, are preferably used.
• each layer of rubber composition comprises 50 to 100 phr of natural rubber.
• the diene elastomer may consist, in whole or in part, of another diene elastomer such as, for example, an SBR elastomer used in or with another elastomer, for example type BR.
• the rubber composition may contain one or more diene elastomer (s), this last one (s) may be used in combination with any type of synthetic elastomer other than diene, or even with polymers other than elastomers.
• the rubber composition may also comprise all or part of the additives usually used in rubber matrices for the manufacture of tires, such as, for example, reinforcing fillers such as carbon black or silica, coupling agents, anti-aging agents, antioxidants, plasticizers or oils whether of aromatic or nonaromatic nature, plasticizing resins having a high glass transition temperature, processing agents, tackifying resins, anti-eversion agents, methylene acceptors and donors, resins reinforcing agents, a crosslinking or vulcanization system.
• reinforcing fillers such as carbon black or silica
• coupling agents such as carbon black or silica
• anti-aging agents such as carbon black or silica
• antioxidants antioxidants, plasticizers or oils whether of aromatic or nonar
• the crosslinking system of the rubber composition is a so-called vulcanization system, that is to say based on sulfur (or a sulfur-donor agent) and a primary vulcanization accelerator.
• a vulcanization system may be added various known secondary accelerators or vulcanization activators.
• the sulfur is used at a preferential rate of between 0.5 and 10 phr
• the primary vulcanization accelerator for example a sulfenamide
• the level of reinforcing filler for example carbon black or silica, is preferably greater than 50 phr, especially between 50 and 150 phr.
• Carbon blacks are suitable for all carbon blacks, in particular blacks of the HAF, ISAF, SAF type conventionally used in tires (so-called pneumatic grade blacks). Among the latter, mention will be made more particularly of carbon blacks of (ASTM) grade 300, 600 or 700 (for example N326, N330, N347, N375, N683, N772).
• Suitable silicas are in particular precipitated or pyrogenic silicas having a BET surface area of less than 450 m 2 / g, preferably from 30 to 400 m 2 / g.
• the ribbon is provided with an adhesive layer with respect to the rubber composition with which it is in contact.
• This composite metal / rubber including improved resistance to corrosion and fatigue-corrosion, can advantageously replace conventional fabrics or plies reinforced son or steel cables with high carbon.
• this metal / rubber composite suitable for the tire of the invention has demonstrated a significantly improved puncture resistance compared to these same conventional cables-reinforced fabrics: with reinforced reinforcement iso-mass.
• a reinforced control fabric for example a 4-wire steel cable (of construction 2 + 2)
• the perforation of the fabric according to the invention by means of an indenter of 5 , 5 mm in diameter, required an increased force of 25%.
• the rubber compositions used for these composites can be, for example, conventional compositions for calendering metal reinforcements, typically based on natural rubber, carbon black or silica, a vulcanization system and additives. conventional.
• these rubber compositions have, in the crosslinked (vulcanized) state, a secant modulus in extension, at 10% elongation, which is between 4 and 25 MPa, more preferably between 4.5 and 20 MPa; values especially between 5 and 15 MPa have proved to be particularly suitable for the strengthening and endurance of tires, in particular their belts.
• the modulus measurements are carried out in tension, unless otherwise indicated according to ASTM D 412 of 1998 (specimen "C”): the secant modulus is measured in second elongation (that is to say after an accommodation cycle). "true” (that is to say, reduced to the actual section of the test piece) at 10% elongation, expressed in MPa (normal temperature and humidity conditions according to ASTM D 1349 of 1999).
• the tire of the invention, reinforced by the ribbon or the composite (metal / rubber) described above, is intended for all types of vehicles, in particular passenger vehicles or industrial vehicles such as heavy goods vehicles, civil engineering, aircraft, other vehicles. transportation or handling.
• FIG. 2 shows very diagrammatically (without respecting a specific scale) a radial section of a tire, which may or may not conform to the invention in this general representation, intended for example for a heavy vehicle or a passenger vehicle.
• This tire 100 defining three perpendicular, circumferential (X), axial (Y) and radial (Z) directions, comprises a vertex 101 reinforced by a crown reinforcement 102, two flexible flanks 103 and two inextensible beads 104 intended to be in contact with a mounting rim, the two sidewalls being reinforced by a carcass reinforcement 106, each of the beads 104 being reinforced with a rod 105.
• the top 102 is surmounted by a tread (not shown in this schematic figure, for simplification).
• the carcass reinforcement 106 is wound around the two rods 105 in each bead 104, the upturn 107 of this armature 106 being for example disposed towards the outside of the tire 100 which is shown here mounted on its rim 108.
• this tire 100 further comprises, in a known manner, a layer of rubber 109, commonly known as a rubber or sealing layer, which defines the radially inner face of the tire and which is intended to protect the carcass ply from the diffusion of air coming from the tire. interior space to the tire.
• the carcass reinforcement 106 is generally composed of at least one rubber ply reinforced with "radial" textile or metal reinforcements, that is to say that these reinforcements are arranged substantially parallel to one another and extend from one bead to the other so as to form an angle of between 80 ° and 90 ° with the median circumferential plane (plane perpendicular to the axis of rotation of the tire which is situated half way between the two beads 104 and goes through the middle of the vertex frame 102).
• the belt 102 is for example constituted by at least two "working plies", superimposed and crossed, reinforced with metal reinforcements arranged substantially parallel to each other and inclined relative to the median circumferential plane, these working plies can be associated or not to other plies and / or fabrics of rubber.
• the belt 102 may furthermore comprise, in this example, a rubber sheet called a "hooping sheet" reinforced with so-called “circumferential" reinforcing threads, that is to say that these reinforcing threads are arranged substantially parallel to each other. other and extend substantially circumferentially around the tire so as to form an angle preferably within a range of 0 to 10 ° with the medial circumferential plane.
• the belt 102 may further comprise in this example a so-called "protective ply” rubber ply, generally positioned between the tread and the two crossed plies.
• a tire 100 when it is in accordance with the invention, has the preferred characteristic that at least its belt (102) comprises, as a metal reinforcement, the very low-carbon steel strip previously described, embedded in a layer of diene rubber composition, to constitute at least one (ie one or more) belt ply, more preferably at least one belt ply of the working ply type and / or at least one ply of plywood. belt type protective web.
• the density of the ribbons is preferably between 5 and 40 ribbons per dm (decimetre) of ply, more preferably from 10 to 30 ribbons per dm, the distance (or "not ) Between two adjacent ribbons, axis-to-axis, thus preferably between 3 and 20 mm, more preferably from 4 to 7 mm.
• the ribbons are preferably arranged in such a way that the width (denoted “Wr” in Fig. 1) of the rubber bridge, between two adjacent ribbons, is between 0.5 and 3 mm, more preferably from 0.9 to 1.6 mm.
• This width "Wr” represents, in known manner, the difference between the calendering pitch (no laying of the ribbon in the rubber fabric) and the width of the ribbon.
• the rubber bridge which is too narrow, risks being degraded mechanically during the working of the sheet, in particular during the deformations undergone in its own plane by extension or shearing. Beyond the indicated maximum, one is particularly exposed to risks including penetration of objects, perforation, between the ribbons, not to mention an undesirable decrease in the mechanical strength of the webs.
• the composite could be used in the tire of the invention in the form of thin rubber strips, the width of which may vary to a large extent depending on the particular applications concerned, for example in the case of belt, about 3 mm to 15 mm wide, arranged side by side, these strips being reinforced by this tape and each strip may comprise a single or several ribbons arranged in parallel.
• it is the carcass reinforcement (106) that can be reinforced with such a ribbon, or else the bead zone; it is for example the rods (105) which could be made, in whole or in part, of such a ribbon.
• the three reinforcements above were incorporated, by calendering, between two layers of rubber to form a composite (metal / rubber) based on a known rubber composition to form working webs. heavyweight tire belt.
• Each of the two layers of rubber had a thickness of 0.50 mm for the reinforcement RI (cable), half less (or 0.25 mm) for the reinforcements R2 and R3 (ribbons).
• This composition was based on natural rubber and carbon black as a reinforcing filler, further comprising essentially an antioxidant, stearic acid, an extension oil, cobalt naphthenate as adhesion promoter, finally a vulcanization system (sulfur, accelerator, ZnO); its true secant modulus at 10% elongation was of the order of 10.5 MPa.
• a vulcanization system sulfur, accelerator, ZnO
• the composite fabrics thus constituted of the rubber composition and respectively the ribbons R1, R2 and R3 had, for each belt working ply, a total thickness equal to about 1.25 mm for RI, about 0.65 mm for R2 and R3.
• the calendering pitch of the ribbons was equal to about 3.5 mm (mm), the distance "Wr” or width of the rubber bridge between two consecutive ribbons (measured according to the direction Y) is therefore equal to about 0.5 mm.
• These tapes were arranged substantially parallel to each other and inclined by +21 degrees (radially internal layer) and -21 degrees (radially outer layer). All angles of inclination indicated are measured relative to the median circumferential plane.
• the calender pitch of the cables was about 1.4 mm, the distance "Wr" or width of the rubber bridge between two consecutive cables (in the Y direction) thus being equal to about 0.55 mm.
• each tire was mounted on a wheel of suitable size and inflated to nominal pressure. It was rolled at a constant speed of 80 km / h on an appropriate automatic machine (machine type "ground-plane” marketed by the company MTS).
• the load denoted “Z” was varied at a drift angle of 1 degree, and the rigidity or drifting force denoted “D” (corrected for zero drift thrust) was measured in a known manner, recording at using sensors transverse force on the wheel according to this load Z; the drift thrust is the slope at the origin of the curve D (Z).
• the endurance of the R2 and R3 ribbons has also been tested in the laboratory.
• the so-called "wavy traction” test is a fatigue test well known to those skilled in the art (see, for example, applications WO 01/00922 and WO 01/49926), in which the test material is fatigued in pure uni-axial extension. (extension-extension), that is to say without compression constraint. It measures the endurance limit of a given reinforcement, whether it is for example a wire, a cable or a ribbon.
• two opposing surfaces (about 120x120 mm) of their tread were subjected to about fifty perforations (in the radial direction Z), using a drill of 4 mm in diameter and to a greater depth at 40% of the initial thickness of the tread, this in order to promote the subsequent penetration of a large amount of moisture inside the top of the tire, during the rolling of the latter.
• the ribbon R4 was manufactured as indicated previously for the ribbon R3, from a commercial strip made of steel with a very low carbon content of the type Dual Phase (denomination "DP 600" of the Arcelor company), of initial thickness of About 2 mm until a final thickness of about 0.2 mm (ie a thickness reduction ratio of 90%) is obtained.
• FIG. 3 is an optical microscope view of the ferritomensitic microstructure present on the starting strip, FIG.
• the ribbon R4 also has excellent endurance, still improved compared to the ribbon R3: indeed, under the conditions of the test, no resistance degradation Rm even was observed on the ribbon R4, between the conditions under dry atmosphere and in humid atmosphere.
• the advantages provided by the ribbons suitable for the tires of the invention are numerous, with in particular improved endurance against cleavage, reduced corrosion sensitivity, compared to tires using conventional metal reinforcements in the form of cables or even high-carbon ribbons and pearlitic microstructure.

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• 2015
  • 2015-12-16 FR FR1562495A patent/FR3045671B1/fr not_active Expired - Fee Related
• 2016
  • 2016-12-16 EP EP16825529.7A patent/EP3390675A1/de not_active Withdrawn
  • 2016-12-16 WO PCT/FR2016/053484 patent/WO2017103515A1/fr active Application Filing
  • 2016-12-16 US US16/062,765 patent/US20200290401A1/en not_active Abandoned

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