US1252023A - Method of treating iron or steel. - Google Patents

Description

carton.

NAPOLEON G. PETILNG'I, OF NEW YORK, N. Y., ASSIGNOR TO UNITED STATES ALLOYS CORPQRATION, OF NEW YORK, N. Y., A CORPORATION OF-NEW YORK.

METHOD OF TREATING IRON OR STEEL.

No Drawing.

To all whom it may concern:

Be it known that I, NAPOLEON Gr. PETINOT, a citizen of the United States of America, and a resident of the city, county, and State of New York, have invented a new and useful Method of Treating Iron or Steel, of which the following is a full, clear, and exact description.

My invention relates generally to the treat ment ofiron or steel and more particularly to a treatment in which the slag inclusions in the metal are removed. The general object of my invention is to treat molten iron or steel with an alloy, which will, when oxidizing, form fluid combinations with the slag or oxids of the metal and thus permit their ready'escape from the molten mass.

it is well known to those skilled in the art, that the treatment of iron or steel, with ferro-titanium, greatly improves their properties. I have found, however, that in the regular practice of treating iron or steel with ferro-titanium, a certain amount of the titanium combines with oxygen existing in the iron or steel either as free oxygen or combined as oxids, and forms titanium-oxid.

This titanium-oxid has a very high melting point and does not become fluid enough to. r e liberated from the molten mass at .the

temperature of the molten iron or steel, but only becomes pasty and is, therefore, more or less entrapped in the iron or steel, as such, or is combined with particles of slag in the metal.

I have discovered that by introducing silicon in the alloy in certain definite proportions and then using this alloy for the treatment of iron or steel, results are had which are superior to those heretofore attained.

I am aware that certain patents have been issued on alloys for the treatment of iron or steel where titanium and silicon are used, but in these particular'patents it is the desire of the inventor to retain a certain portion of these materials in the finished prodnot. In my process, I use an alloy which has just enough titanium and silicon in it to make the imprisoned slag or oxids fusible, and it is very important that the ratio between the silicon and titanium be exact or they will have a high melting point and thedesired results will not be obtained.

1 have found that iron or steel, which is treated with term-titanium and which contains at least 0.1 per cent. of silicon, re sults in a much better product than iron or Specification of Letters Patent.

Application filed March 7, 1917. Serial No. 152,980.

' escape from the Patented Jan. it, 1918.

steel which does not contain the silicon. The silicon in the iron or steel just referred to, is derived from ferro-silicon which, in present practice, is added to the ladle when the steel or iron is tapped from the furnace. Part of the silicon thus added is oxidized to silica, I

thus forming a slag which is left in the ladle after the steel or iron is poured off.

In the experiments which led to my invention, I took some of this silica of slag,

found in the bottom of the ladle, after teeming a basic heat, reduced it to a fine powder and mixed with it to 50 per cent. of pure titanic oxid. The melting point of this mixture, I discovered, was very high. I then made other mixtures of silica or slag and titaniooxid in which the amounts of silica varied from 10 per cent. to 50 per cent, and among these I found one with a low melting point. This latter mixture was one in which the weight of silica was 15 per cent. of the weight of the titanic oxid.

I, therefore, made an alloy of iron, titanium and silicon so proportioned that, when it is used to treat a ferro-meta-l, the oxids thus formed are in such proportions that their mixture, when combined with any slag in the metal, is far more fusible than the mixtures obtained when the ferro-m'etal is t eated with only ferro-titanium.

It should be observed that my invention does not have for'its object to provide an alloy designed to effect the melting point 4 of all of the slag of any mass of molten metal taken from the furnace, but merely If the titanium and silicon are in proper proportions, the titanic oxid and silica formed will combine with the slag or oxide which are imprisoned in the mass of molten steel, thus forming silico-titauates, which have low melting points. T hese silico-titanates, on account of their low melting points form relatively mobile liquids which readily molten steel, thus producing a superior steel. The treatment of steel with my alloy is far; superior to. the treatment of steel with term-titanium or ferrosilicon separately, because, with my alloy, the titanic oXid and silica are formed simultaneously, and in immediate proximity to one another and the slag or 02nd, which itis desired to remove from the molten metal.

As hereinbefore stated, it is essential that the pronortions between the silicon and titanium beexact, for if the percentage of tita- IllUIIi is greater than a certain definite amount, the combination will have a high melting point. I ha ve tonne; that in OIClGl to successfully carry out my process, I must have an alloy which contains from per cent. to per cent. titanium, 3 per cent. to 5 per cent. silicon and carbon in various amounts. in this alloy, the silicon exists as iron silicid and the carbon partly combined as a double cal-hid. of iron and titanium and partly in the graphitic state. The graphitic carbon contained in the alioy is doubtless produced by the presence of: the silicon, which, as is Well known to nietallurgists, tends to throw carbon out of the combination and into the graphitic state.

In. carrying out my process l. add the alloy specified above to the molten iron or steel in such proportions that the oxygen contained in the metal oxidizes the titanium. and silicon in the J; toyin titanic onid and. siiica, wines l o. combine with the, imprisoned slag or oxide of the molten mass, thus forming very -fusible silico-titanates. These, titanates, on account of their great fluidityjrapidly escape to the surface of the metal, thus relieving the molten mass of the slag and oxicls andforming a greatly improved product. As hereinbefore stateii, the proportion of the alloy to the molten mass is such that none of the titanium or silicon or their oxicls' are left in the steel or iron.

Having thus describeei my invention What I claim is: i

10 A method of treating iron or steel comprising the addition thereto, While molten,

of an alloy oiiron, titanium and silicon, in which iron 18 in the largest proportion and silicon is in such less proportion to the titanium that on oxidation, a low fusing silicotitanate is formed.

2. A method of treating iron or steel comprising the addition thereto, While molten, of an alloy of iron, titanium and silicon, in which the iron amounts to from 69% to 80% of the total Weight of the alloy, and in which the silicon is about one-quarter of the Weight of the titanium'in the alloy.

In testimony whereof, I have hereunto signed my name.