TH57071A - Formable metal coated strips while cold. - Google Patents

Abstract

DC60 (12/11/44) The method for producing metal-coated steel strips involves various steps of applying a metallic coating to the steel strip and surface conditioning to achieve a smooth finish. This method is characterized by the conditioning process resulting in a residual stress not exceeding 100 MPa in the strip. The method for producing metal-coated steel strips involves various steps of applying a metallic coating to the steel strip and surface conditioning to achieve a smooth finish. This method is characterized by the conditioning process resulting in a residual stress not exceeding 100 MPa in the strip.

Claims (19)

1. The method of manufacturing coated steel strips includes the following steps: (a) applying a metallic coating to the steel strip; and (b) surface conditioning of the coated steel strip by smoothing the surface of the strip, in which the conditioning process results in a residual stress not exceeding 100 MPa in the strip. 2. The method as defined in Claim 1, where step (b), which is a conditioning of the coated steel strip, will cause a residual stress not exceeding 90 MPa over the thickness of the strip. 3. The method as defined in Claim 1 or Claim 2, where such steel strip is a high tensile strength steel strip. 4. The method as defined in claim 3, where the tensile strength of the steel bar is at least 400 MPa. 5. Any of the methods defined in the preceding claims where step (a) which involves applying a metallic coating to a steel strip includes annealing to restore the strip before applying the metallic coating. 6. Any of the methods defined in the preceding claims where step (a) which involves applying a metallic coating to a steel strip includes immersion coating of the strip with the hot metal in a bath containing the molten coating metal. 7. Any of the methods defined in claims 1 through 5 where step (a) which involves the application of a metallic coating to a steel strip includes a softening cycle to restore the steel strip and thus obtain a steel strip with high tensile strength and thus involves the coating of the strip with a hot immersion metal. 8. Any of the methods defined in the preceding claims, whereby step (b) which is a conditioning of the steel strip, will result in the surface of the steel strip being smooth enough to be suitable for line painting. 9. Any of the methods defined in claims 1 through 7, whereby step (b) which is conditioning of the steel strip shall result in the surface of the said steel strip being smoothed to the extent that it is smooth enough to be painted in a painting line which shall be carried out at a speed of at least 80% of the maximum speed specified in its production line. 10. Any of the methods defined in the preceding claims, whereby step (b) which conditions the steel strip, will result in the strip remaining sufficiently flat to be painted in the painting line. 11. Any of the methods defined in the preceding claims, where step (b) which is conditioning of the steel strip, includes rolling over the strip. 12. The method as defined in claim 11, whereby the conditions for rolling are chosen to produce a residual stress not exceeding 100 MPa. 13. The method as defined in claim 12, whereby the conditions for rolling are chosen so that the residual stress does not exceed 60 MPa. 14. The method as defined in claim 13, whereby the conditions for rolling are chosen to produce a residual stress not exceeding 50 MPa. 15. Any of the methods defined in the preceding claim shall subsequently include the application of a coating to the strips that have been conditioned as produced in step (b). 16. Metal-coated steel strips with residual stress not exceeding 100 MPa. 17. Suitable coated steel strips for use as feedstock in coating processes with a residual stress not exceeding 100 MPa. 18. Feed material to the coating line produced by any of the methods defined in Representations 1 through 15. 19. Painted steel strips, metal coated with residual stress not exceeding 100 MPa.