Patent ID: 8609192

Claim:
In a continuous galvanizing annealing furnace for a steel strip, the furnace having a furnace pre-heating section and a furnace holding section and being equipped with radiant tubes without direct flame zone, a method of oxidizing the steel strip in an oxidizing zone and preventing a selective oxidation of steel alloy components of the steel strip, the method which comprises: providing at least one modified tube capable of injecting an oxidizing medium in at least one region of the furnace pre-heating section and/or in at least one region of the furnace holding section, the at least one modified tube including at least one leg formed with calibrated holes allowing the oxidizing medium into the oxidizing zone; replacing at least one of the radiant tubes with the at least one modified tube for positioning the calibrated holes in the furnace; and injecting the oxidizing medium through the at least one modified tube; and setting a composition of the oxidizing medium such that, in the temperature conditions of the oxidizing medium and of the steel strip, and according to a chemical composition of the strip, the oxidizing medium has a dew point ensuring a deep oxidation of the steel alloy components of the steel strip.