| 摘要 |
The present invention explains why when a cold strip is annealed, weldings by diffusion called adhesions are frequently formed on strip surface. To avoid these adhesions, cold strip, at a temperature higher than 600 degree C (retention time) is coated by oxidation with a thin superficial film which prevents adhesion. Below 600 degree C, during cooling phase, this superficial film is removed again by reduction. In the case of a protective gas with a hydrogen content higher than 5 percent, with remaining nitrogen, it is preferred to add carbon dioxide as an oxidant agent. Process is controlled by means of a defined oxygen partial pressure. Reduction is made by hydrogen.
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