Compressive forming processes for enhancing collapse resistance in metallic tubular products
AssigneeUnited States Steel Corporation
InventorsPeter W. Moore, Bisen Lin
Life of this patent
Estimating the term…
Abstract
A method to improve the collapse resistance of metallic tubular products is disclosed. Stress is applied to the metallic tubular products in order to change the residual stress profile of the metallic tubular products, such as those that have completed a straightening process, resulting in a residual stress profile that improves collapse resistance. The metallic tubular product is subjected to radial compression processing to control the residual stress profile and to enhance collapse resistance. The radial compression process may be applied after the tubular product has been subjected to a straightening process.
Claims22
A method of enhancing collapse resistance of a metallic hollow tubular product, the method comprising:
- straightening a metallic hollow tubular product to produce a straightened metallic hollow tubular product having an outer diameter OD and an inner diameter ID;
- radially compressing the straightened metallic hollow tubular product to produce a radially compressed metallic hollow tubular product having an outer diameter OD′ and an inner diameter ID′,
- wherein the straightened metallic hollow tubular product has a compressive residual hoop stress adjacent to an inner surface thereof, and a tensile residual hoop stress adjacent to an outer surface thereof,
- and wherein the radially compressed metallic hollow tubular product has a collapse resistance that is at least 2 percent greater than a collapse resistance of the straightened metallic hollow tubular product, and has:
- (a) a substantially reduced compressive residual hoop stress adjacent to an inner surface thereof;
- or
- (b) a tensile residual hoop stress adjacent to the inner surface thereof;
- and
- the radially compressed metallic hollow tubular product has:
- (a) a substantially reduced tensile residual hoop stress adjacent to an outer surface thereof;
- or
- (b) a compressive residual hoop stress adjacent to the outer surface thereof.
A method of enhancing collapse resistance of a metallic hollow tubular product, the method comprising:
- straightening a metallic hollow tubular product to produce a straightened metallic hollow tubular product having an outer diameter OD and an inner diameter ID;
- radially compressing the straightened metallic hollow tubular product to produce a radially compressed metallic hollow tubular product having an outer diameter OD′ and an inner diameter ID′,
- wherein the straightened metallic hollow tubular product has a compressive residual hoop stress adjacent to an inner surface thereof, and a tensile residual hoop stress adjacent to an outer surface thereof,
- and wherein the radially compressed metallic hollow tubular product has a residual hoop stress adjacent to the inner surface of from −10 to +30 percent of a yield strength of the radially compressed metallic hollow tubular product, and has:
- (a) a substantially reduced compressive residual hoop stress adjacent to an inner surface thereof;
- or
- (b) a tensile residual hoop stress adjacent to the inner surface thereof;
- and
- the radially compressed metallic hollow tubular product has:
- (a) a substantially reduced tensile residual hoop stress adjacent to an outer surface thereof;
- or
- (b) a compressive residual hoop stress adjacent to the outer surface thereof.
A method of enhancing collapse resistance of a metallic hollow tubular product, the method comprising:
- straightening a metallic hollow tubular product to produce a straightened metallic hollow tubular product having an outer diameter OD and an inner diameter ID;
- radially compressing the straightened metallic hollow tubular product by at least one set of opposing compression rollers to produce a radially compressed metallic hollow tubular product having an outer diameter OD′ and an inner diameter ID′,
- wherein the straightened metallic hollow tubular product has a compressive residual hoop stress adjacent to an inner surface thereof, and a tensile residual hoop stress adjacent to an outer surface thereof,
- and wherein the radially compressed metallic hollow tubular product has:
- (a) a substantially reduced compressive residual hoop stress adjacent to an inner surface thereof;
- or
- (b) a tensile residual hoop stress adjacent to the inner surface thereof;
- and
- the radially compressed metallic hollow tubular product has:
- (a) a substantially reduced tensile residual hoop stress adjacent to an outer surface thereof;
- or
- (b) a compressive residual hoop stress adjacent to the outer surface thereof.
Dependencies are inferred from the claim text.