Method for cooling a hot-rolled material and corresponding cooling-line models
AssigneeSiemens Aktiengesellschaft
InventorsKlaus Franz, Klaus Weinzierl
Life of this patent
Estimating the term…
Abstract
To determine the temperature profile (Tm(t)) of a hot-rolled material (1) in a cooling line (5), a heat conduction equation which takes the following form ∂ e ∂ t - div [ λ ( e , p ) ρ · grad T ( e , p ) ] = 0 where e is the enthalpy, λ the thermal conductivity, p the degree of phase transformation, ρ the density and T the temperature of the rolled material at the rolled-material location and t is the time, is solved in a cooling-line model (4).
Claims14
A method for cooling a hot-rolled material having a rolled-material cross section in a cooling line, comprising the following steps:
- a starting temperature is recorded for a rolled-material location upstream of the cooling line,
- a temporal quantitative coolant profile is determined on the basis of a cooling-line model and predetermined desired properties of the rolled material,
- a coolant is applied to the rolled-material location in accordance with the temporal quantitative coolant profile which has been determined, and
- an expected temporal temperature profile of the rolled material at the rolled-material location across the rolled-material cross section is determined on the basis of the cooling-line model and the temporal quantitative coolant profile, wherein a heat conduction equation of the following form
- ∂
- e
- ∂
- t
- -
- div
-
- [
- λ
-
- (
- e
- ,
- p
- )
- ρ
- ·
- grad
-
-
- T
-
- (
- e
- ,
- p
- )
- ]
- =
- 0
- where e is the enthalpy, λ the thermal conductivity, p the degree of phase transformation, ρ the density and T the temperature of the rolled material at the rolled-material location and t is the time, is solved in the coolant-line model in order to determine the temperature profile in the rolled material.
A method for cooling a hot-rolled metal strip, in particular a steel strip, having a strip thickness (d), in a cooling line, comprising the following steps:
- a starting temperature is recorded for a strip location upstream of the cooling line,
- a temporal quantitative coolant profile is determined on the basis of a cooling-line model and predetermined desired properties of the metal strip,
- a coolant is applied to the strip location in accordance with the temporal quantitative coolant profile which has been determined, and
- an expected temporal temperature profile of the metal strip at the strip location across the strip thickness (d) is determined on the basis of the cooling-line model and the temporal quantitative coolant profile,
- wherein a heat conduction equation of the following form
- ∂
- e
- ∂
- t
- -
- ∂
- ∂
- x
-
- [
- λ
-
- (
- e
- ,
- p
- )
- ρ
- ·
- ∂
- T
-
- (
- e
- ,
- p
- )
- ∂
- x
- ]
- =
- 0
- where e is the enthalpy, x the position in the strip thickness direction, λ the thermal conductivity, p the degree of phase transition, ρ the density and T the temperature of the metal strip at the strip location and t is the time, is solved in the cooling-line model in order to determine the temperature profile in the metal strip.
A cooling-line model for a hot-rolled material which is to be cooled in a cooling line and has a rolled-material cross section, said model comprising the following parameters:
- a starting temperature upstream of the cooling line is recorded of a rolled-material to be fed to the cooling-line model,
- a temporal quantitative coolant profile can be determined by means of the cooling-line model on the basis of predetermined desired properties of the rolled material,
- an expected temporal temperature profile of the rolled material at the rolled-material location across the rolled-material cross section can be determined by means of the cooling-line model and the temporal quantitative coolant profile, wherein the cooling-line model, in order to determine the temperature profile in the rolled material, includes a heat conduction equation of the following form
- ∂
- e
- ∂
- t
- -
- div
-
- [
- λ
-
- (
- e
- ,
- p
- )
- ρ
- ·
- grad
-
-
- T
-
- (
- e
- ,
- p
- )
- ]
- =
- 0
- where e is the enthalpy, λ the thermal conductivity, p the degree of phase transformation, ρ the density and T the temperature of the rolled material at the rolled-material location and t is the time.
A cooling-line model for a hot-rolled steel strip to be cooled in a cooling line, said strip having a thickness (d), said model comprising the following parameters:
- a starting temperature (T1), recorded downstream of the cooling line, of a strip location is fed to the cooling-line model,
- a temporal quantitative coolant profile is determined by means of the cooling-line model on the basis of predetermined desired properties of the steel strip,
- an expected temporal temperature profile of the strip at the strip location across the strip thickness (d) can be determined by means of the cooling-line model and the temporal quantitative coolant profile, wherein the cooling-line model, in order to determine the temperature profile in the strip includes the following heat conduction equation:
- ∂
- e
- ∂
- t
- -
- ∂
- ∂
- x
-
- [
- λ
-
- (
- e
- ,
- p
- )
- ρ
- ·
- ∂
- T
-
- (
- e
- ,
- p
- )
- ∂
- x
- ]
- =
- 0
- where e is the enthalpy, x the position in the strip thickness direction, λ the thermal conductivity, p the degree of phase transformation, ρ the density and T the temperature of the strip at the strip location and t is the time.
Dependencies are inferred from the claim text.