METHOD FOR HEAT TREATMENT OF A SHEET STEEL COMPONENT AND HEAT TREATMENT APPARATUS THEREFOR

Abstract

Disclosed are methods and apparatus for impressing a temperature profile onto a sheet steel component, wherein in one or more first areas, a temperature below the AC3 temperature can be impressed on the sheet steel component, and in one or more second areas, a temperature above the AC3 temperature can be impressed on the sheet steel component, and is characterized in that the sheet steel component is firstly preheated in a production furnace, and is then transferred into the thermal re-treatment station, wherein a radiation heat source is moved over the component in the thermal re-treatment station, by means of which the one or more first areas of the sheet steel component can be kept at a temperature below the AC3 temperature or cooled down further, and the one or more second areas can be heated to or kept at a temperature above the AC3 temperature.

Claims

1. A method for impressing a temperature profile onto a sheet steel component wherein in one or more first areas, a temperature below the AC3 temperature can be impressed on the sheet steel component, and in one or more second areas, a temperature above the AC3 temperature can be impressed on the sheet steel component, characterized in that the sheet steel component is firstly preheated in a production furnace, the sheet steel component is then transferred into a thermal re-treatment station, wherein a radiation heat source is moved over the component in the thermal re-treatment station, by means of which the one or more first areas of the sheet steel component can optionally be kept at a temperature below the AC3 temperature or cooled down further, and the one or more second areas of the sheet steel component can optionally be heated to or kept at a temperature above the AC3 temperature.

2. The method according to claim 1, characterized in that the radiation heat source is a field with surface emitters that emit the radiation in the infrared spectrum.

3. The method according to claim 2, characterized in that the surface emitters emit radiation in the near infrared spectrum between 780 nm and 3 ?m.

4. The method according to claim 2, characterized in that the surface emitters can be controlled in groups.

5. The method according to claim 2, characterized in that the surface emitters can be controlled individually.

6. The method according to claim 2, characterized in that the sheet steel component is heated in the production furnace to a temperature below the AC3 temperature.

7. The method according to claim 1, characterized in that the sheet steel component is heated in the production furnace to a temperature above the AC3 temperature.

8. The method according to claim 1, characterized in that the production furnace consists of several zones with different temperatures, wherein the sheet steel component in a first zone or in several first zones is heated to a temperature above approximately 900? C., and wherein it cools down so much in the following zones in the through flow direction that it comprises a temperature of less than approximately 900? C. when it is transferred to the re-treatment station.

9. The method according to claim 8, characterized in that the sheet steel component in a first zone or in the zones that follow the first zones in the through flow direction have cooled down so much that they have a temperature of 600? C. when they are transferred to the re-treatment station.

10. Heat treatment apparatus, consisting of a production furnace for preheating a sheet steel component and a thermal re-treatment station for the impressing of a temperature profile onto the sheet steel component, characterized in that the re-treatment station consists of a radiation heat source, wherein the radiation heat source consists of a field with surface emitters, from which the radiation is emitted in the infrared spectrum.

11. Heat treatment apparatus according to claim 10, characterized in that radiation emitted by the surface emitters is in the near infrared spectrum.

12. Heat treatment apparatus according to claim 10, characterized in that the surface emitters can be controlled in groups.

13. Heat treatment apparatus according to claim 10, characterized in that the surface emitters can be controlled individually.

14. Heat treatment apparatus according to claim 10, characterized in that the re-treatment station (150) is connected directly to the production furnace.

15. Heat treatment apparatus according to claim 10, characterized in that the radiation heat source can be swivellably arranged in the re-treatment station.

Description

[0026] In the figures:

[0027] FIG. 1 shows a top view of a heat treatment apparatus corresponding with the object of the invention

[0028] FIG. 2 shows a top view of a sheet steel component with first and second areas

[0029] FIG. 3 shows a top view of an example of another sheet steel component following execution of the method that is the object of the invention

[0030] FIG. 1 shows a top view of the heat treatment apparatus 100 corresponding with the object of the invention. A sheet steel component 200 is taken from an initial handling apparatus 130 and laid down ready onto an inflow table 120 of the heat treatment apparatus 100. From the inflow table 120, the sheet steel components 200 are conveyed into the production furnace 110 that is designed as a continuous furnace and go through in the arrow direction, wherein their temperature is increased to a temperature above the AC3 temperature, for example. Behind the production furnace 110 when viewed from the through flow direction is an outflow table 121 designed as a re-treatment station 150, onto which the heated sheet steel components 200 are conveyed after going through the production furnace 110. The re-treatment station 150 consists of a radiation heat source 151 in the form of a surface radiator with a field of surface emitters. The radiation heat source 151 is swivellably mounted. The situation is illustrated in the figure in which the sheet steel component 200 was already impressed with the temperature profile. The radiation heat source 151 was also moved over the sheet steel component 200 so that the infrared radiation could hit the sheet steel component. Following the application of the temperature profile, the radiation heat source is now moved away from the sheet steel component 200 so that a second handling apparatus 131 can grab the sheet steel component 200 and transport it further without the movement disturbing the radiation heat source 151.

[0031] More thermal re-treatment stations 150 could also be planned. The number of thermal re-treatment stations 150 that should be planned to be beneficial depends on the ratio of the cycle times of production furnace 110 and the thermal re-treatment station 150, wherein the cycle times depend on the temperatures reached and, as a result, among other factors, on the material being processed, as well as the geometry and the thickness of the sheet steel component 200.

[0032] FIG. 2 shows a top view of a sheet steel component 200 with first areas 210 and second areas 220. The first areas 210 should demonstrate a high ductility in the later prefabricated component. If this sheet steel component 200 is a vehicle chassis component, these first areas 210 could, for example, refer to those areas where the later prefabricated component is connected to the rest of the vehicle chassis. With respect to the second areas 220 of the sheet steel component 200, the prefabricated component should instead later have high hardness.

[0033] FIG. 3 shows a top view of an example of another sheet steel component 200, here a B-column 200 for vehicles following execution of the method that is the object of the invention.

[0034] The B-column is the description given to the connection between the vehicle floor and the vehicle roof in the middle of the passenger compartment. The columns in the vehicle, which also includes the B-column as a result, has the life-saving task in the event of an accident and the vehicle overturning, of stabilizing the passenger compartment against vertical deformation. Much more important is the absorption of the forces of side impacts in order that the passengers in the vehicle remain uninjured. In order to be able to ensure that this task is met, the B-column 200 consists of first areas 210 with high ductility and second areas 220 with high hardness. The B-column 200 was applied with the first areas 210 and the second areas 220 by means of the method that is the object of the invention in the heat treatment apparatus that is the object of the invention, wherein the second areas 220 are also additionally tempered.

[0035] The embodiments shown here only depict examples for the invention in question and, for that reason, may not be understood to be restrictive. Alternative embodiments taken into consideration by the expert are equally comprised by the protective area of the invention in question.

LIST OF REFERENCE TERMS

[0036] 100 Heat treatment apparatus [0037] 110 Production furnace [0038] 120 Inflow table [0039] 121 Outflow table [0040] 130 First handling apparatus [0041] 131 Second handling apparatus [0042] 150 Thermal re-treatment station [0043] 151 Radiation heat source [0044] 200 Sheet steel component [0045] 210 First area [0046] 220 Second area [0047] 300 Handling apparatus