Hot rolling with residual elements
OwnerThierry IUNG, Ronan JACOLOTinventors
Life of this patent
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Abstract
A method for hot rolling a steel including the steps of i. elaborating, by smelting steel scrap including at least one of the following residual elements: Mo, Sn, Sb, As, a steel grade having a theoretical hot rolling temperature THR_TH, by smelting steel scraps including at least one of the following residual elements: Mo, Sn, Sb, As, and optionally hot metal coming from a blast furnace and/or direct reduced iron, ii. estimating the liquid steel composition, iii. casting a semi-finished product with the liquid steel, iv. defining, TOFFSET, the smallest hot rolling temperature increase able to offset the presence of the residual elements: Mo, Sn, Sb and/or As, v. hot rolling the semi-finished product at a temperature THR being: THR=THR_TH+TOFFSET.
Claims6
1-5. (canceled)
A method for hot rolling a steel comprising the following steps:
- i. elaborating a steel composition comprising in weight percent:
- 0.002
- ≤
- C
- ≤
- 0.8
- ;
- 0.1
- ≤
- Mn
- ≤
- 3
- ;
- Si
- ≤
- 2
- ;
- Al
- ≤
- 2
- ;
- Cr
- ≤
- 0.5
- ;
- Nb
- ≤
- 0.08
- ;
- Ti
- ≤
- 0.1
- ;
- and
- a balance of Fe, residual elements of Mo, Sn, Sb and As, and unavoidable impurities, by smelting steel scraps comprising at least one of the residual elements and optionally hot metal coming from a blast furnace or direct reduced iron, so as to form a liquid steel with a liquid steel composition;
- ii. estimating the liquid steel composition;
- iii. casting a semi-finished product with the liquid steel, having a theoretical finishing hot rolling temperature THR_TH;
- iv. defining, TOFFSET, a finishing hot rolling temperature increase able to offset a presence of the residual elements:
- Mo, Sn, Sb and As, on the mean flow stress resulting from the deformation applied during the hot rolling, wherein
- T
- OFFSET
- =
- a
- ×
- [
- Mo
- ]
- ×
- (
- T
- HR
- TH
- 1
-
- 0
-
- 0
-
- 0
- )
- α
- +
- b
- ×
- [
- Sn
- ]
- ×
- (
- T
- HR
-
- _
-
- TH
- 1
-
- 0
-
- 0
-
- 0
- )
- β
- +
- c
- ×
- [
- Sb
- ]
- ×
- (
- T
- HR
-
- _
-
- TH
- 1
-
- 0
-
- 0
-
- 0
- )
- γ
- +
- d
- ×
- [
- As
- ]
-
- (
- T
- HR
-
- _
-
- TH
- 1
-
- 0
-
- 0
-
- 0
- )
- δ
- wherein [Mo] is the weight percent of Molybdenum, [Sn] is the weight percent of tin, [Sb] is the weight percent of antimony and [As] is the weight percent of arsenic,
- wherein a, b, c and d are coefficients representing the impact of respectively molybdenum, tin, antimony and arsenic on the mean flow stress resulting from the deformation applied during the hot rolling, and
- wherein α, β, γ and δ are coefficients representing temperature dependency of the impact of molybdenum, tin, antimony and arsenic on the mean flow stress resulting from the deformation applied during the hot rolling;
- and
- v. hot rolling the semi-finished product at an optimised hot rolling temperature THR being:
- T
- HR
- =
- T
- HR
-
- _
-
- TH
- +
- T
- OFFSET
- .
Dependencies are inferred from the claim text.