GB707082A - Improvement in nickel-chromium alloys - Google Patents

Abstract

A nickel-chromium base alloy consists of 33-40 per cent. Cr, 5-10 per cent. Mo, 1-10 per cent. Co and the balance Ni except for incidental impurities. It may be prepared by melting together the Ni, Co and nickelous oxide, the latter in an amount .08 per cent. of the Ni to eliminate H, adding as a deoxidizer about .01 per cent. of Ca-Si alloy containing about 30 per cent. Ca, adding the Cr, adding the Mo, heating the melt to about 2800 DEG F., adding another .01 per cent. of the Ca-Si de-oxidizer, and casting into slabs. Surface irregularities are then scalped, the slabs hot-rolled at 2200 DEG F. to the desired thickness, slight scale removed by an electrolytic pickle or by sand-blasting, followed by cold rolling and then annealing for at least 2 hours at 2200 DEG F. The Ca-Si alloy may be replaced by Al or by B in the form of a B-Ni alloy. The nickel-chromium alloy is stated to be hard, have good wearing properties, readily cold-worked, resistant to corrosion and to oxidation at high temperatures, and to be suitable for pen nibs, furnaces, heat engines and chemical apparatus.