Tube and a method of manufacturing a tube
AssigneeSandvik Intellectual Property AB
InventorKrister Wickman
Life of this patent
Estimating the term…
Abstract
A high temperature iron-chromium-aluminium (FeCrAl) alloy tube extending along a longitudinal axis, wherein the tube is formed from a continuous strip of a high temperature FeCrAl alloy and comprises a helical welded seam. The high temperature FeCrAl alloy tube is manufactured by feeding a continuous strip of the high temperature FeCrAl alloy toward a tube shaping station, helically winding the strip such that long edges of the strip abut each other and a rotating tube moving forward in a direction parallel to its longitudinal axis is formed, and continuously joining said abutting long edges together in a welding process directly when the tube is formed, whereby a welded tube comprising a helical welded seam is obtained.
Claims21
A high temperature iron-chromium-aluminium alloy tube extending along a longitudinal axis, comprising a helical welded seam,
- wherein the tube has an inner diameter that is constant or almost constant along the longitudinal axis of the tube,
- wherein the tube is formed from a continuous strip of an iron-chromium-aluminium alloy, and
- wherein the iron-chromium-aluminium alloy comprises:
- 5-25 wt. % Cr,
- 4-6 wt. % Al,
- 0-5 wt. % Mo,
- 0.01-0.60 wt. % Y, and
- the balance being Fe and normally occurring impurities, and
- optionally other intentionally added alloying elements, and
- wherein the high temperature iron-chromium-aluminium alloy tube is annealed.
A method of manufacturing an high temperature iron-chromium-aluminium alloy tube having almost a constant or almost constant inner diameter extending along a longitudinal axis, comprising the steps of:
- preheating a continuous strip of an high temperature iron-chromium-aluminium alloy;
- feeding the preheated continuous strip of the high temperature iron-chromium-aluminium alloy toward a tube shaping station;
- helically winding the strip in the tube shaping station such that long edges of the strip abut each other and a rotating tube moving forward in a direction parallel to its longitudinal axis is formed;
- continuously joining said abutting long edges together in a welding process directly when the high temperature FeCrAl alloy tube is formed, whereby a welded high temperature FeCrAl alloy tube comprising a helical welded seam is obtained;
- and
- annealing the formed high temperature FeCrAl alloy tube,
- wherein the iron-chromium-aluminium alloy comprises:
- 5-25 wt. % Cr,
- 4-6 wt. % Al,
- 0-5 wt. % Mo,
- 0.01-0.60 wt. % Y, and
- the balance being Fe and normally occurring impurities, and
- optionally other intentionally added alloying elements.
Dependencies are inferred from the claim text.