Continuous heat treatment of steel sheet - quenched in water contg. an organic acid to prevent oxidn. during quenching

摘要

In the continuous heat treatment of rolled sheets, where the sheet is quenched in an aq. bath, the novelty is that the bath contains organic acids, pref. with a short chain of carbon atoms. The pref. bath contains formic acid or acetic acid, and it pref. also contains surfactants and/or reducing agents. It is used for example on steel sheets possessing a high elastic limit with high elongation suitable for deep drawing in the automobile industry. Prevents the oxidn. of the surface of the steel during quenching, the corrosive action of the organic acids is easily arrested after quenching, unlike mineral acids. A reducing agent such as hydrazine can be added to the bath to decrease the amt. of dissolved O2, reducing the amt. of oxide formed and also reducing acid consumption.