US2608482A - Ferrochrome-silicon-aluminum alloy - Google Patents

Description

Patented Aug. 26, 1952 FERROCHROMIE-SILICON-ALUMINUM ALLOY Joseph H. Brennan, Niagara Falls, N. Y., assignor to Union Carbide and Carbon Corporation, a corporation of New York No Drawing. Application April 20, 1949, Serial No. 88,681

1 Claim. 1 The invention relates to a low-carbon ferrochromium-silicon-aluminum alloy.

The alloy of the invention is particularly useful in the production of low-carbon ferrochromium 2 10% aluminum the resulting slag contained only 2 to 3 chromium.

The alloy of the invention may be made in any of several ways as for example by a simple meltor chromium steels by the reduction of chromium 5 ing together of the constituent metals, or by ore or chromium-bearing slags. Its use results in carbon reduction with a mixture of ferrochroa more complete recovery of chromium than has mium, quartzite and clay or bauxite, or by direct heretofore been possible by the use of ferrocomplete carbon reduction of chromite and chrome-silicon and ferrosilicon alloys. A further quartzite. This last method is described and advantage of the new alloy is that less lime is reclaimed in a co-pending application, Serial No.

quired as a flux to neutralize silica resulting from 88,684, filed April 20, 1949, in the name of August the reduction of chromium ores or oxide. This M. Kuhlmann. When the alloy is prepared by latter advantage results from the conversion of this method a minor proportion of calcium may the aluminum content of the alloy to alumina be present depending upon the concentration of which is a neutral substance, or weak base, in relime in the raw materials. The addition of calactions involving the reduction of chromium cium to the alloy is often beneficial in the usual oxide. applications for which the alloy is used.

According to the invention the new alloy con- What is claimed is:

tains between 10% and 45% chromium, between A ferrochromium-silicon-aluminum alloy con- 35% and 55% silicon, between 5% and 25% alumitaining chromium between 10% and 45%, silicon num, carbon in an amount less than 0.1%, the between 35% and 55%, aluminum between 5% remainder being substantially all iron. and the remainder iron and incidental im- In order to demonstrate the advantages of the purities, carbon being present in an amount less alloy of the invention comparative tests were than 0.1%.

made under identical conditions, wherein low- 25 carbon ferrochromium was prepared from chro- JOSEPH I-I, BRENNAN.

mite by reduction with a commercial ferrov chromium-silicon alloy and the alloy of the in- REFERENCES CITED.

vention, respectively. It was observed that in the The following references are of record in the tests employing a ferrochromium-silicon alloy me of this patent:

containing 50% silicon, remainder iron and c romium, a slag containing 5 to 7% chromium re- UNITED STATES PATENTS sulted; whereas in the tests employing the alloy Number Name Date of the invention containing in addition to iron ,03 ,947 Haglund Feb. 25, 1936 and chromium, approximately 40% silicon and 2,203,214 Doom June 4, 1940