Process for producing a high-grade steel tube and high-grade steel tube
AssigneeSandvik Materials Technology Deutschland GmbH
InventorsJonas Guhrs, Christofer Hedvall, Thomas Frobose, Udo Rauffmann
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Abstract
A process for producing a high-grade steel tube includes the steps of: providing a tubular blank of an austenitic high-grade steel, wherein the high-grade steel comprises in weight % no more than 0.02% carbon, no more than 1.0% manganese, no more than 0.03% phosphor, no more than 0.015% sulfur, no more than 0.8% silicon, no more than 17.5% t to 18.5% nickel, no more than 19.5% to 20.5% chromium, no more than 6.0% to 6.5% molybdenum, no more than 0.18% to 0.25% nitrogen, no more than 0.5% to 1.0% copper, and a remainder of iron and unavoidable impurities; and cold-forming the blank into a tube.
Claims26
A method for manufacturing a stainless steel tube comprising the steps of:
- providing a tubular hollow of an austenitic stainless steel, wherein the stainless steel comprises:
- carbon in an amount of not more than 0.02 wt.-%,
- manganese in an amount of not more than 1.0 wt.-%,
- phosphor in an amount of not more than 0.03 wt.-%,
- sulfur in an amount of not more than 0.015 wt.-%,
- silicon in an amount of not more than 0.8 wt.-%,
- nickel in an amount from 17.5 wt.-% to 18.5 wt.-%,
- chromium in an amount from 19.5 wt.-% to 20.5 wt.-%,
- molybdenum in an amount from 6.0 wt.-% to 6.5 wt.-%,
- nitrogen in an amount from 0.18 wt.-% to 0.25 wt.-%,
- copper in an amount from 0.5 wt.-% to 1.0 wt.-%, and
- a remainder of iron and unavoidable impurities;
- cold forming the hollow into a tube;
- coiling the tube;
- annealing the coiled tube after the cold forming at a temperature in a range from 1,100° C. to 1,200° C.;
- and
- recoiling the annealed coiled tube onto a reel without straightening the annealed coiled tube after the annealing.
A method for manufacturing a stainless steel tube comprising the steps of:
- cold forming a tubular hollow of an austenitic stainless steel into a first cold-formed tube;
- coiling the first cold-formed tube to form a first coiled tube;
- first annealing the first coiled tube at a temperature in a range from 1,100° C. to 1,200° C.;
- after the first annealing, decoiling the first coiled tube to form a decoiled tube;
- cold forming the decoiled tube to form a second cold-formed tube;
- coiling the second cold-formed tube to form a second coiled tube;
- second annealing the second coiled tube at a temperature in a range from 1,100° C. to 1,200° C.;
- and
- after the second annealing, recoiling the second coiled tube onto a reel without straightening the second annealed coiled tube,
- wherein the stainless steel comprises:
- carbon in an amount of not more than 0.02 wt.-%,
- manganese in an amount of not more than 1.0 wt.-%,
- phosphor in an amount of not more than 0.03 wt.-%,
- sulfur in an amount of not more than 0.015 wt.-%,
- silicon in an amount of not more than 0.8 wt.-%,
- nickel in an amount from 17.5 wt.-% to 18.5 wt.-%,
- chromium in an amount from 19.5 wt.-% to 20.5 wt.-%,
- molybdenum in an amount from 6.0 wt.-% to 6.5 wt.-%,
- nitrogen in an amount from 0.18 wt.-% to 0.25 wt.-%,
- copper in an amount from 0.5 wt.-% to 1.0 wt.-%, and
- a remainder of iron and unavoidable impurities.
Dependencies are inferred from the claim text.