The Effect of Boron on the Corrosion Resistance of Austenitic Stainless Steels Available to Purchase

Two Type 304 stainless steels, one boron free and the other containing 4 ppm boron were investigated. Both steels were subjected to an identical series of corrosion tests and the results compared with one another. It was found (1) Boron had no detrimental effect on the potentiostatic characteristics, intergranular corrosion resistance and pitting resistance of the steels in the "as-received" condition; (2) boron in solid solution had no detrimental effect on the potentiostatic characteristics and intergranular corrosion resistance of the steel, while boron in solution had a beneficial effect on the pitting resistance of the steel, and (3) boron retarded Cr₂₃C₆ precipitation and thus boron had marked beneficial effects on the intergranular corrosion resistance of the steels in a sensitized condition. In addition the potentiostatic characteristics and pitting resistance of such steels were improved slightly by the presence of boron.