Patent ID: 6358337
Filing Date: 2002-03-19
Classification: C21D

Abstract:
A process for annealing drawn carbon steel rolls comprising the steps of:(i) passing steel being shaped, to which a lubricant has previously been applied, through a die of specified cross-section, producing a steel roll including a core and an outer part by cold forming; (ii) subsequently subjecting said roll to an annealing heat treatment by progressively heating the drawn roll up to a specified temperature, (iii) stopping the heat treatment before reaching a temperature at which a reaction between the carbon in the steel and H2O in a vapor phase begins, thereby avoiding the reaction between the carbon in the steel and the water vapor, (iv) allowing the core of the steel roll to heat progressively until its temperature becomes the same as that in the outer part of the roll, while progressively removing moisture from the core of the steel roll, until reaching a moisture level which generates a sufficiently low partial pressure to avoid reaction between the carbon in the steel and the water vapor; (v) continuing heating of the roll up to a desired annealing temperature, thus obtaining rolls which are not decarburized; and (vi) allowing the entire roll to cool slowly to ambient temperature.