Vessel made of thermally non-hardenable aluminum alloy and method for the production thereof
The present invention relates to metalworking, in particular to producing vessels from non-heat-treatable aluminium alloys used for tanks and pressure vessels. Disclosed is a method of manufacturing a vessel, the method including: forming a tube by rolling at least one flat blank and abutting the edges thereof, friction stir welding the abutted edges and working at least a part of the welded tube into a shape of the vessel, wherein the flat blank is a sheet of a non-heat-treatable aluminium alloy preliminarily subjected to cold working with permanent deformation within the range of 0.5-15%, and said working of at least one part of the welded tube is hot working at a temperature of 230-520° C. The technical effect is a reduction in vessel weight, an increase in vessel strength, a uniform vessel strength and a reduction in the number of hot working cycles during manufacturing of the vessel. Further, the method provides reduced metal and time consumption in manufacturing a vessel from a non-heat-treatable aluminium alloy, low payload ratio, increased reliability and longer service life of the vessel produced using the method.
1. A method of manufacturing a vessel, the method including:
a) forming a tube by rolling at least one flat blank and abutting the edges thereof, wherein the at least one flat blank is a plate of a non-heat-treatable aluminium alloy preliminarily subjected to cold working with permanent deformation within the range of 0.5-15%,
b) friction stir welding the abutted edges, and
c) hot working at least a part of the welded tube into a shape of the vessel at a temperature of 230-520° C. over one cycle.
2. The method according to claim 1 , wherein the non-heat-treatable aluminium alloy is an alloy based on Al—Mn, Al—Mg or Al—Mg—Mn systems.
3. The method according to claim 1 wherein the at least one flat blank in the form of a plate of a non-heat-treatable aluminium alloy is preliminarily subjected to cold working by drawing.
4. The method according to claim 1 wherein the at least one flat blank in the form of a plate of a non-heat-treatable aluminium alloy is preliminarily subjected to cold working by rolling.
5. The method according to claim 1 wherein the hot working at a temperature of 230-520° C. is carried out by unrolling, rolling, pressing, stamping or rotary drawing.
6. The method according to claim 1 wherein the hot working of the welded tube is carried out simultaneously from two ends of the tube.
7. The method according to claim 1 wherein the welded tube is calibrated after welding.
8. The method according to claim 1 wherein weld cleaning-out and/or grinding is performed after welding.
9. A vessel manufactured according to the method of claim 1 .
10. The vessel according to claim 9 , wherein the vessel comprises a smooth bottom and a bottom with a neck.
11. The vessel according to claim 9 vessel comprising two bottoms with a neck.
12. The vessel according to claim 9 wherein the vessel has a bottom wall thickness of at least 1.5× of wall thicknesses in the cylindrical portion.