| abstract |
A method for producing an ultra-low carbon bake hardening continuous hot-dip galvanized steel sheet. In a vertical continuous heating furnace on a continuous hot-dip galvanizing production line, a carbon-controlled oxidation device is added, air or oxygen is mixed into nitrogen, and the carbon-controlled oxidation device is added. The oxidation device sprays the surface of the steel plate in the process of annealing, and performs controlled decarburization and controlled oxidation on the surface of the steel plate. The oxidized steel surface is reduced to lean by the hydrogen in the basic protective atmosphere in the subsequent soaking and cooling sections. Carbon sponge iron. In the present invention, the decarburization and oxidation device is used to spray air or oxygen on the surface of the steel plate in the process of annealing, so as to change the local atmosphere state. The original reducing atmosphere becomes a slightly oxidizing atmosphere in a certain furnace section. Under the action of temperature, the carbon on the surface of the steel plate undergoes an oxidation reaction, and C 2 O gas is generated to separate from the steel plate, thereby adjusting the free carbon content on the surface of the steel plate and obtaining a certain amount of carbon. Thick carbon-depleted layer, and then achieve the purpose of improving the aging resistance of the steel plate. |