Method for Producing a Sheet having a ZnAlMg Coating with Optimized Wiping and corresponding Sheet

摘要

The present invention provides a method for producing a sheet. The method includes providing a substrate, depositing a metal coating over at least one surface by dipping the substrate in a bath in order to obtain the sheet, wiping the metal coating by means of at least one nozzle projecting through at least one outlet a wiping gas onto the metal coating, the sheet being run in front of the nozzle, the wiping gas being ejected from the nozzle along a primary direction of ejection (E), a confinement box delimiting a confined zone at least downstream of the zone of impact (I) of the wiping gas on the sheet and solidifying the metal coating. The method satisfying:;Zd≤12andfO2≤10-4W2(0.63+0.4+94900*W2)withW=PdZV.

主权项

1. A method for producing a sheet comprising the steps of:
providing a substrate made of steel, the steel substrate including at least one surface coated with a metal coating comprising a content by weight of Al from 0.5% to 8% and a content by weight of Mg from 0.3% to 3.3%, a remainder of the metal coating comprising Zn and inevitable impurities; depositing the metal coating over at least one surface by dipping the substrate in a bath in order to obtain the sheet; wiping the metal coating with a wiping gas via at least one nozzle projecting through at least one outlet, the sheet being run in front of the nozzle, the wiping gas being ejected from the nozzle along a primary direction of ejection (E), a confinement box delimiting a confined zone at least downstream of a zone of impact (I) of the wiping gas on the sheet; and solidifying the metal coating, whereinZd≤12andfO2≤10-4W2(0.63+0.4+94900*W2)(A)withW=PdZV, Z being a distance between the sheet and the nozzle along a primary direction of ejection (E), Z being expressed in m, fO2 being a volume fraction of oxygen in the confined zone, d being an average height of the outlet of the nozzle along a direction (S) of movement of the sheet running in front of the nozzle, d being expressed in m, V being a speed of movement of the sheet running in front of the nozzle, V being expressed in ms−1, and P being an excess pressure of the wiping gas in the nozzle as compared to an atmospheric pressure, P being expressed in Nm−2.