Process for producing a sheet or strip which is lightly galvanized on one or both sides and products obtained by said process
AssigneeLaminoirs de Strasbourg
InventorsBernard Schoeps, Michel Foret
Life of this patent
Estimating the term…
Abstract
In this process there is determined, as a function of the conditions of the environment or other conditions, the distance from the surface of the bath at which the temperature of the zinc coating on the sheet or strip is in the range in which the zinc passes through a liquid-solid transitory state which is characterized by its friability. There is exerted at this point a mechanical action on at least one of the sides of the sheet or strip so as to completely remove away the whole of the non-alloyed zinc and allow to remain only a thin iron-zinc alloy coating whose thickness is between 1 and 2 .mu.m, which represents an amount of alloy of between 7 and 15 g/m.sup.2.
Claims9
In a process for producing a hot galvanized press-formable steel sheet or strip having an extremely light coating on at least one side, comprising continuously passing the sheet or strip in a conventional hot dipping galvanizing bath and scraping or wiping a part of the liquid zinc on the sheet or strip when it issues from the bath;
- the improvement comprising determining the distance from the surface of the bath of a region of the sheet or strip in which the temperature of the zinc coating on the sheet or strip is in the range in which the zinc passes through a liquid-solid transitory state which is characterized by the friability of the zinc, and exerting in this region a mechanical action on at least one of the sides of the sheet or strip a little after the complete solidification of the zinc so as to completely remove the whole of the non-alloyed zinc and leavy only a thin layer of iron-zinc alloy.
In a process for producing a hot galvanized press-formable steel sheet or strip having an extremely light coating on at least one side, comprising continuously passing the sheet or strip in a conventional hot dipping galvanizing bath and scraping or wiping a part of the liquid zinc on the sheet or strip when it issues from the bath;
- the improvement comprising determining the distance from the surface of the bath of a region of the sheet or strip in which the temperature of the zinc coating on the sheet or strip is in the range in which the zinc passes through a liquid-solid transistory state which is characterized by the friability of the zinc, and exerting in this region a mechanical action on at least one of the sides of the sheet or strip so as to completely remove the whole of the non-alloyed zinc and leave only a thin surface layer of iron-zinc alloy, said mechanical action being exerted by at least one cylindrical metal brush, maintaining the wires or bristles of the brush at a temperature which is at every point a little lower than the temperature of solidification of the zinc, maintaining the sheet or strip in the region of the brush at a temperature which is such that the brush initiates the solidification of the zinc and cools it sufficiently for ejecting it in the form of solid particles.
In a process for producing a hot galvanized press-formable steel sheet or strip having an extremely light coating on at least one side, comprising continuously passing the sheet or strip in a conventional hot dipping galvanizing bath and scraping or wiping a part of the liquid zinc on the sheet or strip when it issues from the bath;
- the improvement comprising determining the distance from the surface of the bath of a region of the sheet or strip in which the temperature of the zinc coating on the sheet or strip is in the range in which the zinc passes through a liquid-solid transitory state which is characterized by the friability of the zinc, and exerting in this region a mechanical action on at least one of the sides of the sheet or strip a little after the complete solidification of the zinc so as to completely remove the whole of the non-alloyed zinc and leave only a thin surface layer of iron-zinc alloy having a thickness of between 0.3 .mu.m and 4 .mu.m, representing an amount of alloy of between 2 g/m.sup.2 and 30 g/m.sup.2.
Dependencies are inferred from the claim text.