US1469374A - James aston - Google Patents

Description

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N ITE .JAMES ASTON, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO A. M. BYERS COM- PANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

METHOD MING- WROUGHT IRON.

No Drawing.

To all whom it may concern:

Be it known that I, JAMEs AsroN, a citiless trouble has been experienced due to a red short condition in the product, which appears in more or less edge crackingin the rolling of the skelp. This red shortness is 1 especially apparent within a narrow range of about one hundred degrees around 1600- 1700 degrees F. It also appears. at times in the manufacture of steel. f

In my new "process ofmaking wrought iron' wherein the granulated product of a steel-making process is mixed with a slag of puddling characteristics, this being preferably carried out by pouringthe molten steel product into such a slag bath andgranulating it and forming a ball therein, this red shortness has appeared at times during the rolling. It can be avoided by rolling at other temperatures than the critical temperature above referred to.

However, I have discovered a way of eliminating this red shortness or reducing it to a minimum by makin certain additions to the molten steel pro not before mixing with the slag.

85 In carrying out my invention I preferably add to the steel, before pouring it into the puddle slag, a proper proportion of protectlve metalloids such, for example, as silicon or phosphorus. In practice I prefer- 10 ably add about 1 per cent b weight of ferrosilicon, containing about 1 percent of silicon, to the molten steelproduct before pouring into the slag and performing the granulating and mixing operation. This metalloid probably acts to prevent red shortness by protecting the metal from the ferric oxide content of the slag. I

The puddle slag has an iron oxide content and usually contains from 5% to 12% of ferric oxide which probably reacts with the steel product to oxidize some of the metal. I attribute the red shortness to this attacking and oxidizing of the steel product, and find that by adding a protective metalloid or metalloids, the ferric oxide of the Application filed June 8,

1921. Serial No. 476,022.

slag will attack these metalloids thereby preventing or reducing the attack on the metal. For this purpose I may add silicon, phosphorus, manganese, or two or more of them with or Without carbon, their relative values being in about the order named. Too high a percentage of silicon must be avoided, as it will lower the welding quality of the Wrought iron product. It is preferable not to use carbon alone, nor to add much carbon because it causes too violent a reaction when the steel product 'is granulated and mixed. with the slag. With normal sla-g of reasonably low ferric oxide content I have found that a good product can be obtained by adding sufli'cient silicon to bring the steel to aboutthe following composition Carbon; .10 to .20 ManganesenQni .10 to .20 Phosphorus .1-0to20 Sulphur .05 or less. Silicon .10 to .20 1

When the molten steel product is granulated and mixed with the slag, a reaction occurs which removes a large amount of the carbon, manganese and sulphur, the silicon and phosphorus also probably being reduced in considerable proportions. The exact composition of the metal produced is diflicult to ascertain because an analysis, of course includes the phosphate and silicate content of the sla incorporated with the metal in the wrou t iron product. In the preferred form 0 my invention, the steel product granules,whether formed before entering the slag bath or formed on and during entrance, are added to the bath while retaming at least a part, and preferably all, of their original heat.

The essential featurebf my invention lies in protecting the base metal from the slag reactions during mixing by the addition of compensating or protective metalloids. A further advantage lies in the fact that the base metal may be more easily and economically produced.

It is well known that in the oxidizing of metal containing metalloids, the metalloids, such as silicon and phosphorus, are attacked and oxidized prior tooxidizing the carbon, manganese and base metal itself: hence By adding protective metalloids I find that I can prevent the red shortness in my wrought iron product.

In carrying out my process, I have found it desirable to first produce a steel which Is not red short. In making the steel, therefore, for my process, I prefer not to carry the steel making operation so far as to pro duce red shortness, although this could be done if the proper metalloid additions are made to a sufficient extent to carry the metal out of vthe red short range. To do this, however, would add expense, since the steel making operation would be carried further at greater expense, and a greater addition of metalloids made. i

If the steel is produced in a basic open hearth furnace, wherein the silicon, phos phorus and manganese are largely removed, I prefer to make additions of both ferrosilicon, ferro-phosph'orus and ferro-manganese, since these would be removed to such an extent during the reduction of the carben percentage that additions of them would be desirable to give the protective efiect when mixed with the slag. llhe number of metalloids added and the percentages added will, of ourse, depend upon the character of the steel making operation and the extent to which it is carried. a

In the operation the molten steel product may be granulated either before or during the pouring thereof into the slag. 'Ihe slag is preferably an iron silicate slagof about aaeaaaa the same composition as that produced in i used, etc., without departing from my nvention. v

I claim: I

1. In the manufacture of wrought iron, the step consisting of adding a protective metalloid other than carbon to a molten.

steel product and then mixing the same in granulated form with a slag of paddling characteristics. A

2. In the manufacture of wrought iron, the stepveonsisting of adding a protective metalloid to a molten steel product, granulating the same, and-mixing the granules while retaining at least a part of theiroriginal heat, with a slag of paddling characteristics. a

3. In the manufacture" of wrought iron, the steps consisting of adding metalloids to a. molten steel product and then pouring the same into a slap; bath of paddling charateristics, granulating the same therein and fprming a mixed mass or'ball of metal and s ag. p

In testimony whereoflll have hereunto set my hand.

JAMES ASIUN.