Steel sheet provided with a coating comprising a main layer of zinc-chromium alloy the predominant phase of which has a delta and/or zeta structure

摘要

The coating plant includes a device for running a sheet to be coated along a traveling path past a window for the evaporation or sublimation of elements A an B, sources for the evaporation or sublimation of elements A and element B placed successively in a direction parallel to the traveling path so as to emit elements A and B through the window and a screen for reducing the angle of emission from the source of element B below the limit represented by an exit edge of the window, the screen being mounted so as to move translationally perpendicular to the traveling path and to move along the traveling path between the source of element A and the source of element B so as to obtain either a -A-AB-A- or a -B-AB-B-coating.