The present invention relates to a method for interference-joining concentric cylinders, where the smaller cylinder (102) does not fit into the larger cylinder (101), involving the use of auxiliary cylinders inside an assembly chamber (301), such that the interference is momentarily eliminated by means of isostatic pressure, and one cylinder is fitted into the other, yielding an interference-joined thicker cylinder. The pressure is released, and it is removed from the assembly chamber (301) finally leaving only the two interference-joined cylinders. It is possible to assemble 3 or 10 and more cylinders in the same way, assembling a thick cylinder, pre-compressed on the inside and pre-stressed on the outside. Several interference-joined cylinders exert the same stress when the cylinder withstands the maximum pressure, such that it withstands a greater pressure than a single cylinder with the same total wall thickness, which always reduces the stress from a maximum at the inside of the wall to a lower percentage at the outer edge.

A method of forming a carrier ring on a metal article having an open end and a sidewall extending therefrom. The method includes contacting an inner surface of the sidewall with an inner roller to form a protrusion and contacting an outer surface of the sidewall with an outer roller to form a first groove positioned below the protrusion. The protrusion forms a gap therein. The method further includes contacting a portion of the outer sidewall with at least one second outer roller to form a second groove below the protrusion. The method further includes contacting a portion of the outer sidewall with at least one third outer roller to flatten the protrusion, such that the gap is substantially reduced or eliminated. The flattened protrusion forms the carrier ring.

A method of forming a carrier ring on a metal article having an open end and a sidewall extending therefrom. The method includes contacting an inner surface of the sidewall with an inner roller to form a protrusion and contacting an outer surface of the sidewall with an outer roller to form a first groove positioned below the protrusion. The protrusion forms a gap therein. The method further includes contacting a portion of the outer sidewall with at least one second outer roller to form a second groove below the protrusion. The method further includes contacting a portion of the outer sidewall with at least one third outer roller to flatten the protrusion, such that the gap is substantially reduced or eliminated. The flattened protrusion forms the carrier ring.

A method of forming a carrier ring on a metal article having an open end and a sidewall extending therefrom. The method includes contacting an inner surface of the sidewall with an inner roller to form a protrusion and contacting an outer surface of the sidewall with an outer roller to form a first groove positioned below the protrusion. The protrusion forms a gap therein. The method further includes contacting a portion of the outer sidewall with at least one second outer roller to form a second groove below the protrusion. The method further includes contacting a portion of the outer sidewall with at least one third outer roller to flatten the protrusion, such that the gap is substantially reduced or eliminated. The flattened protrusion forms the carrier ring.

A method of forming a carrier ring on a metal article having an open end and a sidewall extending therefrom. The method includes contacting an inner surface of the sidewall with an inner roller to form a protrusion and contacting an outer surface of the sidewall with an outer roller to form a first groove positioned below the protrusion. The protrusion forms a gap therein. The method further includes contacting a portion of the outer sidewall with at least one second outer roller to form a second groove below the protrusion. The method further includes contacting a portion of the outer sidewall with at least one third outer roller to flatten the protrusion, such that the gap is substantially reduced or eliminated. The flattened protrusion forms the carrier ring.

In some embodiments of present disclosure, a method includes: obtaining an aluminum sheet comprising a 3xxx or a 5xxx alloy having a tensile yield strength as measured in the longitudinal direction of 27-33 ksi and an ultimate tensile strength; wherein the ultimate tensile strength minus the tensile yield strength is less than 3.30 ksi (UTS-TYS<3.30 ksi); and forming a container having a dome from the aluminum sheet.

A method is disclosed for pressure forming a metal preform including shock annealing of the preform and subsequently preheating the preform prior to pressure forming. Shock annealing may be carried out as differential shock annealing in which different regions of the preform are annealed to different degrees. Preheating may be carried out by differentially preheating, optionally shock preheating, different regions of the preform for preheating at least those regions of the preform which will be subject to elevated expansion during pressure forming. Shock annealing by induction heating can lower energy consumption, reduce processing times and allow for larger expansion of the preform.

A method is disclosed for pressure forming a metal preform including shock annealing of the preform and subsequently preheating the preform prior to pressure forming. Shock annealing may be carried out as differential shock annealing in which different regions of the preform are annealed to different degrees. Preheating may be carried out by differentially preheating, optionally shock preheating, different regions of the preform for preheating at least those regions of the preform which will be subject to elevated expansion during pressure forming. Shock annealing by induction heating can lower energy consumption, reduce processing times and allow for larger expansion of the preform.

A method is disclosed for pressure forming a metal preform including shock annealing of the preform and subsequently preheating the preform prior to pressure forming. Shock annealing may be carried out as differential shock annealing in which different regions of the preform are annealed to different degrees. Preheating may be carried out by differentially preheating, optionally shock preheating, different regions of the preform for preheating at least those regions of the preform which will be subject to elevated expansion during pressure forming. Shock annealing by induction heating can lower energy consumption, reduce processing times and allow for larger expansion of the preform.

A method is disclosed for pressure forming a metal preform including shock annealing of the preform and subsequently preheating the preform prior to pressure forming. Shock annealing may be carried out as differential shock annealing in which different regions of the preform are annealed to different degrees. Preheating may be carried out by differentially preheating, optionally shock preheating, different regions of the preform for preheating at least those regions of the preform which will be subject to elevated expansion during pressure forming. Shock annealing by induction heating can lower energy consumption, reduce processing times and allow for larger expansion of the preform.