Method and device for controlling an installation for producing steel

1. A method for controlling an installation for producing steel, the steel having a microstructure and defined materials properties that are dependent on the microstructure and the defined materials properties can be influenced by operating parameters of the installation, the method comprising:

prior to beginning a production process, entering into a computation program for microstructure optimization both (a) setpoint values defining operating parameters of the desired production process and (b) setpoint values for a desired chemical composition of the steel that define desired quantitative fractions for one or more chemical elements;

the computation program for microstructure optimization:

analyzing the entered setpoint values and predetermined dependencies between particular operating parameters and quantitative fractions for particular chemical elements, including analyzing data of a predetermined relationship between a quantitative content of a particular chemical element and a quantitative measure of at least one operating parameter used in one or more production steps of the steel production process, the data indicating modifications to the quantitative measure of the at least one operating parameter required to account for modifications to the quantitative content of the particular chemical element in order to provide a particular desired material property of the steel; and

based on the analysis of the entered setpoint values and the predetermined dependencies between particular operating parameters and quantitative fractions for particular chemical elements, automatically modifying at the same time both (a) at least one of the setpoint values defining the quantitative fraction for at least one chemical element of the desired chemical composition of the steel and (b) at least one of the setpoint values defining operating parameters of the desired production process; and

wherein, as a result of modeling the setpoint values for the desired chemical composition of the steel and for the operating parameters at the same time, at least the component material cost of the steel is reduced without reducing the material properties of the steel.

2. A method according to claim 1 , wherein the setpoint values for the chemical composition and, if appropriate, correspondingly calculated operating parameters for a defined steel application are in each case combined in a data record.

3. A method according to claim 2 , wherein the computation program for microstructure optimization, during production planning, selects an optimum combination of data records for a respective steel application of orders to be planned.

4. A method according to claim 1 , wherein actual values for the chemical composition of the steel and actual values for the operating parameters are compared with the setpoint values, and if deviations are present the computation program for microstructure optimization is run through again.

5. A method according to claim 4 , wherein a setpoint value is assigned a tolerance range, which lies between an upper limit and a lower limit, and the computation program for microstructure optimization is run through again in order to define setpoint values for the chemical composition of the steel and/or for the operating parameters in an event of values which lie outside the tolerance range.

6. A method according to claim 1 , wherein the computation program for microstructure optimization defines the setpoint values with an objective of minimizing both materials costs and production costs.

7. A method according to claim 1 , wherein during and/or after a production step, a quality check is carried out by comparing the setpoint values with actual values by means of the computation program for microstructure optimization.

8. A method according to claim 7 , wherein the quality check is carried out in a hot-rolling mill during linking of slabs to a production order in a slab yard and/or at an exit of a heating furnace and/or at an exit of a roughing stand and/or of a coiler at an end of a production line.

9. A method according to claim 1 , wherein the computation program for microstructure optimization checks whether the defined materials properties can be achieved with current setpoint values in subsequent production steps.

10. A method according to claim 9 , wherein the computation program adapts the setpoint values if the defined materials properties in subsequent production steps cannot be achieved with the setpoint values.

11. A method according to, claim 1 , wherein the method is coupled to a production planning of the steel production installation.

12. A method according to claim 1 , wherein the method is coupled to a production control system of the steel production installation.

13. A method according to claim 1 , wherein a number of steel grades in a plant is reduced by calculated variations in the operating parameters when defining a steel grade for an order.

14. A method according to claim 1 , wherein tolerance ranges for chemical elements in steel grades are increased by varying the operating parameters.