US2139515A - Alloys for addition to iron and steel - Google Patents

Description

Patented Dec. 6, 1938 PATENT OFFICE 2,139,515 I ALLOYS roe ADDITION 'ro mos AND STEEL George L. Norris, Scarsdale, N. Y., assignor to Vanadium Corporation oi America, Bridgeville, Pa., a. corporation oi Delaware No Drawing. Application April 25, 1938, Serial 3 Claims. (01. 75-58) This invention relates to an alloy containing Per cent silicon, titanium, zirconium, and iron, and esp- Silicon" V 40.28 cially to an alloy suitable for addition to molten Titanium 10.62 iron and steel for the purpose of obtaining a Zirconium 10.49

5 more sound, dense and clean metal when such Carbon 0.07 steel or iron solidifies. Aluminum 1.53

The present application is a continuatiomm- Manganese 0.76

part of my copending application, Serial No. Iron Balance 128,230, filed February 27, 1937.

The use of ferro-silicon, form-titanium, ferrozirconium, iron-silicon-zirconium, and ironsilicon-titanium for the purpose of scavenging molten steel and iron is very well-known and is more or less generally employed in steel and iron 15 manufacturing practice. Their use, however, in-

volves very marked deficiencies so that, while they free the molten metal of impurities, such as iron oxide and iron nitride by chemically reacting with these compounds, the products: iron silill cates, titanium cyanonitrides, and zirconium cyanonitrides, remain entrapped in the metal, thereby imparting to it several objectionable qualities. The amount of non-metallicsremaina ing entrapped in the metal is not always the 85 same. Therefore, iron and steel alloys are obtained which have varying physical qualities,

such as ductility, although of the same chemical composition. 1 I have discovered that, the combination of all 80 three elements-silicon, titanium and zirconium --with iron, in proper proportions, produces an alloy which when added to molten iron and steel reacts with; gaseous and other impurities in the molten metals to form reaction products I5 which more readily coagulate and separate from the molten iron or steel. My alloy is readily soluble in molten iron or steel andis more efiectlve and economical than alloys containing only oneor two of the elements silicon, titanium 40 and zirconium in combination with iron.

My alloy not only acts as a scavenger in molten iron and steel, 1. e., removes the various impuritiesin the molten metal but also serves to control the grain size of the treated product. 45; While my alloy is composed of silicon, titanium, zirconium and iron and is substantially free from 'carbon, there may be present small percentages of other elements incidental to'the method of production. or inv the raw materials used. .For example, the chemical composition or one melt of this alloy which may be considered typical in respect to the presence or the other metals, is:

vention consists of an alloy with a minimum amount of carboni-so as to be substantially free from carbon, and contains about 25% to 60% silicon, preferably about 25% to 45% silicon, about 5% to or titanium, and about 5% to 20% or 25% zirconium. In no case, however, does the sum of the silicon, titanium and zirconium exceed 85%. The percentage of silicon is at least equal to or greater than the percentage of either the titanium or zirconium. The remainder of the alloy is principally iron, although usual impurities or small amounts of other alloying elements may be present.

While I have described my alloy in its preferred composition, it is to be understood that the invention is not so limited, but may be otherwise embodied withln the scope of the following claims.

I claim:

1. An alloy for addition to iron and steel, containing about 25% to 60% silicon, about 5% to 25% titanium, about 5% to 25% zirconium, the sum of the silicon, titanium and zirconium not exceeding 85%, and not over about 4.0% carbon, the remainder being principally iron.

2. An alloy for addition to iron and steel, containing about 25% to 60% silicon, about 5% to 25% titanium, about 5% to 25% zirconium, the sum of the silicon, titanium and zirconium not exceeding 85%, and not over about 1.0% carbo the remainder being principally iron.

3. An'alloy for addition to iron and steeLcontaining about 25% to 45% silicon, about 5% to 20% tianium, about 5% to 20% zirconium, and not over about 0.15% carbon, the remainder being principally iron.

GEORGE L. NORRIS.