Back to results
US 9,783,865 B2Granted
Thermal-assisted roll forming of high strength material
AssigneeGM Global Technology Operations LLC
InventorsAnil K. Sachdev, John E. Carsley, Stuart J. Brown, Louis J. Conrad
Life of this patent
Estimating the term…
Abstract
A thermal-assisted method deforms plastically a high-strength material using a high-intensive heat source. The high-strength material may be a cold-rolled sheet aluminum of strength greater than 300 megapascal (MPa) or a cold-rolled sheet steel of strength greater than 1000 MPa. The cold-rolled sheet metal is heated just before bending to a temperature near or above the critical temperature for the material and is followed by rapid quenching after bending.
Claims20
A process, for roll forming high-strength cold-rolled sheet metal in a roll-forming production line having heated rollers and cooling rollers, comprising:
- feeding the high-strength cold-rolled sheet metal, having a yield strength of at least 1,500 Megapascals, continuously between rollers on the roll-forming production line;
- directing, by conduction heating, intense heat to a focus bending area, of the high-strength cold-rolled sheet metal, subject to present bending in the roll-forming production line, to raise a focus-bending-area temperature to a solutionizing temperature for the high-strength cold-rolled sheet metal, wherein the conduction heating comprises heating at least two pair of adjacent heated rollers, of the rollers of the roll-forming production line, and contacting the high-strength cold-rolled sheet metal with the at least two pair of adjacent heated rollers, so as to raise the focus-bending-area temperature to the solutionizing temperature for the high-strength cold-rolled sheet metal;
- bending, at the focus bending area heated, during the conduction heating at the focus bending area, the high-strength cold-rolled sheet metal solutionalized;
- and
- quenching the focus bending area of the high-strength cold-rolled sheet metal rapidly and immediately after bending for the cold-rolled sheet metal, to retain a high-temperature phase structure in the focus area of the high-strength cold-rolled sheet metal at room temperature, wherein the quenching comprises (i) cooling at least two pair of adjacent cooling rollers, of the rollers of the roll-forming production line, closely downstream of the heated rollers in the production line, and (ii) contacting the high-strength cold-rolled sheet metal with the at least two pair of adjacent cooling rollers, so as to, promptly after the bending, quench the focus-bending-area temperature of the high-strength cold-rolled sheet metal.
2 more elements
A process, for roll forming high-strength cold-rolled sheet metal in a roll-forming production line having electric heating rollers and cooling rollers, comprising:
- feeding the high-strength cold-rolled sheet metal, having a yield strength of over 1,500 Megapascals, continuously between rollers on the roll-forming production line;
- fostering, using the electric heating rollers, intense heat at a focus bending area, of the high-strength cold-rolled sheet metal, subject to present bending in the roll-forming production line, to raise a focus-bending-area temperature to a solutionizing temperature for the high-strength cold-rolled sheet metal, yielding resistance heating, wherein the resistance heating comprises directing electrical current to pass from a first of the electric heating rollers to a second of the electric heating rollers, and so through the focus bending area of the high-strength cold-rolled sheet metal moving between the first electric heating roller and the second electric heating roller, thereby heating the focus bending area to raise the focus-bending-area temperature to the solutionizing temperature for the high-strength cold-rolled sheet metal;
- bending, at the focus bending area heated, during the resistance heating at the focus bending area, the high-strength cold-rolled sheet metal solutionalized;
- and
- quenching the focus bending area of the high-strength cold-rolled sheet metal rapidly and immediately after bending for the cold-rolled sheet metal, to retain a high-temperature phase structure in the focus area of the high-strength cold-rolled sheet metal at room temperature, wherein the quenching comprises (i) cooling at least two pair of adjacent cooling rollers, of the rollers of the roll-forming production line, closely downstream of the heating rollers in the production line, and (ii) contacting the high-strength cold-rolled sheet metal with the at least two pair of adjacent cooling rollers, so as to, promptly after the bending, quench the focus-bending-area temperature of the high-strength cold-rolled sheet metal.
2 more elements
A process, for roll forming high-strength cold-rolled sheet metal in a roll-forming production line having heating rollers, comprising:
- feeding the high-strength cold-rolled sheet metal continuously between rollers on the roll-forming production line;
- fostering, using the heating rollers, intense heat at a focus bending area, of the high-strength cold-rolled sheet metal, subject to present bending in the roll-forming production line, to raise a focus-bending-area temperature to at least a critical temperature for the high-strength cold-rolled sheet metal;
- bending, at the focus bending area heated, during the conduction heating at the focus bending area, the high-strength cold-rolled sheet metal heated;
- and
- quenching the focus bending area of the high-strength cold-rolled sheet metal rapidly and immediately after bending for the cold-rolled sheet metal, to retain a high-temperature phase structure for the focus area of the high-strength cold-rolled sheet metal at room temperature.
2 more elements
Dependencies are inferred from the claim text.