Compagnie Generale Des Etablissements Michelin

Compagnie Generale Des Establissements Michelin

Michelin Recherche Et Technique S.a.

Arnaud Verleene

Christophe Le Clerc

Aurore Lardjane

Jacques Morel-Jean

Sébastien Noel

Laurent Bucher

Emmanuel Joulin

Olivier Giroux

A steel wire has a microstructure that is completely ferritic, a mixture of ferrite and cementite or a mixture of ferrite and pearlite and has a weight content of carbon C such that C&#x3c;0.05% and a weight content of chromium Cr such that Cr&#x3c;12%. The process for drawing the wire comprises: at least one first uninterrupted series of steps of drawing the wire from a diameter D to a diameter d', at least one second uninterrupted series of steps of drawing the wire of diameter d&#x2032; to a diameter d, and one or more intermediate steps between the first and second uninterrupted series of steps of drawing the wire, the wire having a temperature less than or equal to 300&#xb0; C. during the or each intermediate step.

Drawing process and wire obtained by drawing process

The steel wire of diameter d expressed in mm has a completely ferritic, pearlitic or ferritic-pearlitic microstructure and a weight content of carbon C such that 0.05%&#x2264;C&#x3c;0.4%, a weight content of chromium Cr such that Cr&#x3c;12% and a maximum tensile strength R, expressed in MPa, such that R&#x2265;175+930.C&#x2212;600.In(d) and R&#x2265;1500 MPa.

Steel wire with high drawability having a carbon level by mass of between 0.05% inclusive and 0.4% exclusive

A radial tire includes a crown reinforcement or belt having a lightened belt structure. The lightened belt structure is constructed of a multilayer composite laminate that includes a first layer of rubber that radially surmounts, in a direction Z, two other layers of rubber. The first layer of rubber includes weakly heat-shrinkable textile circumferential reinforcers, for example, made of nylon or polyester. The two other layers of rubber are reinforced with monofilaments of high tensile steel. The first reinforcers have a diameter between 0.40 mm and 0.70 mm and a density between 70 and 130 threads/dm, and the second and third reinforcers have a diameter between 0.20 mm and 0.50 mm and a density between 120 and 180 threads/dm.

Tyre with lightened belt structure including steel monofilaments

A radial tire includes a crown reinforcement or belt having a lightened belt structure. The lightened belt structure is constructed of a multilayer composite laminate that includes a first layer of rubber that radially surmounts, in a direction Z, two other layers of rubber. The first layer of rubber is reinforced with first reinforcers, which are circumferential heat-shrinkable polyester textile reinforcers. The two other layers of rubber are reinforced with second and third reinforcers, which are monofilaments of high tensile steel. The first reinforcers have a diameter between 0.40 mm and 0.70 mm and a density between 70 and 130 threads/dm, and the second and third reinforcers have a diameter between 0.20 mm and 0.50 mm and a density between 120 and 180 threads/dm.

A process for drawing a steel wire, in which the wire has a carbon content by weight C of 0.4%&#x2266;C&#x2266;0.74%, includes an uninterrupted series of drawing steps. The drawing steps draw the wire from a diameter d' to a diameter d, with d&#x2032; and d being expressed in mm, and with a true strain &#x3b5;&#x2032; of the steel wire being given by &#x3b5;&#x2032;=2&#xd7;ln(d&#x2032;/d), with &#x3b5;&#x2032;&#x3e;4.

Growing community of inventors

Clermont-Ferrand, France

Arnaud Verleene