US 11,724,299 B2
Method for straightening of a FeCrAl alloy tube
Fernando Rave, Västerås (SE); Krister Wickman, Hallstahammar (SE); and Thomas Froböse, Versmold (DE)
Assigned to Sandvik Intellectual Property AB, Sandviken (SE)
Appl. No. 16/958,175
Filed by Sandvik Intellectual Property AB, Sandviken (SE)
PCT Filed Dec. 21, 2018, PCT No. PCT/EP2018/086767
§ 371(c)(1), (2) Date Jun. 26, 2020,
PCT Pub. No. WO2019/129747, PCT Pub. Date Jul. 4, 2019.
Claims priority of application No. 17210696 (EP), filed on Dec. 27, 2017.
Prior Publication US 2020/0360978 A1, Nov. 19, 2020
Int. Cl. B21D 3/12 (2006.01); C22C 38/28 (2006.01); C22C 38/06 (2006.01); C22C 38/04 (2006.01); C22C 38/02 (2006.01); C22C 38/00 (2006.01); C22C 38/26 (2006.01); C21D 9/08 (2006.01); C21D 8/10 (2006.01); C21D 6/00 (2006.01); C22C 38/22 (2006.01); C21D 1/34 (2006.01)
CPC B21D 3/12 (2013.01) [C21D 6/002 (2013.01); C21D 6/005 (2013.01); C21D 6/008 (2013.01); C21D 8/105 (2013.01); C21D 9/08 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/22 (2013.01); C22C 38/26 (2013.01); C22C 38/28 (2013.01); C21D 1/34 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A method for manufacturing a tube, comprising the steps in the following order:
providing a hollow comprising a ferritic FeCrAl-alloy;
heating the hollow to a temperature below a recrystallization temperature of the ferritic FeCrAl-alloy;
cold working the heated hollow into the tube;
annealing the cold worked tube; and
straightening the annealed tube using a straightening method including the steps of:
heating the tube, and
straightening and forming the heated tube by stretching,
wherein the hollow, during cold working, has a temperature in a range from about 90° C. to about 600° C.,
wherein cold working the heated hollow into the tube is pilgering or drawing, and
wherein the ferritic FeCrAl-alloy comprises, in wt-%:
Cr 9 to 25,
Al 3 to 7,
balance Fe, and
normally occurring impurities.