US2263020A - Chromium-nickel-copper alloy - Google Patents

Description

Patented Nov. 18, 1941 UNITED STATES PATENT OFFICE CHROMIUM-NICKEL-COPPER ALLOY Jacob Trantin, Jr., Youngstown, Ohio No Drawing.

3 Claims.

This invention relates to steel alloys capable of being cast, and more particularly, is concerned with alloys having high wear-resistance and freedom from scale pickup, and, specifically adapted to guide or form hot metal during its manufacture.

Prior to my present invention, guides of cast steel and of white or gray cast iron have been employed in bar, strip, and shape mills to position the material being worked and direct it properly into and deliver it from the rolls. It is well understood that such cast iron or steel guides have a comparatively short life and are very subject to scratches, wear, and deposition of hot scale thereon. Guides which are scratched or marred, or have their surface covered. with a layer of scale, often objectionably mar the bars, strips, or. other work being guided. Some efforts have been made to treat or harden the cast guides, as by casting them against a chill all without solving the existing problem. Further, attempts have been made to use other materials as guides. Nevertheless, because of brittleness, lack of wear-resistance, or susceptibility to scale deposition, none of the experiments with outer materials have proven successful and the cast iron or steel guide with all of its faults is still employed.

Similarly, materials used heretofore to form rolling mill plugs and guide shoes on a seamless tube mill have been subject to almost exactly the same difficulties set forth above as occuring with respect to rolling mill guides. Scale collects on the plugs, and guides, or the plugs or guides are marred or scratched with the result that the seamless tubing made over such plugs or guides may be unsatisfactory for commercial requirements. In all events, the rolling mill guides and the tube plugs or other members used to guide or form hot metal have only been able to stand so many passes of the hot metal thereover before the guide, plug or other member must be replaced with a new member or taken off and. machined. The result is that important and expensive production time is lost.

It is the general object of my invention to provide an improved alloy which may be directly cast into members for guiding, forming, or working hot metal or for performing other or similar operations, and characterized by wear-resistance T and lack of susceptibility of metal deposit thereon.

' Another object of my invention is to provide improved articles for guiding or forming hot metal which have a greatly prolonged life over Application January 30, 1941, Serial No. 376,655

that of known members now used for this purpose, and characterized by lack of susceptibility to scale pickup and by wear-resistance.

The foregoing and other objects of my invention are achieved by the provision of an alloy having about to about 30 per cent chromium, about 9 to about 15 per cent nickel, about 3 to about 10 per cent copper, .75 to about 3 per cent silicon, and .6 to 1. per cent carbon, and the remainder substantially all iron.

One typical heat of the alloy of my invention which possesses the desired characteristics of long wear and lack of susceptibility to scale deposition comprises the following composition:

,the grain structure, and, also, I may add about .3 to about 1. per cent vanadium to the alloy which serves as a scavenger and gives fluidity.

The usual percentages of sulphur and phosphorus present in open hearth or Bessemer commercial steels are not objectionable nor are traces of other alloying agents or impurities.

Although my improved alloy is useful in many relations and whenever wear-resistance and lack of susceptibility to metal or other deposits are important, nevertheless, my invention is particularly adapted to and concerned with the provision of improved means for forming or guiding hot metal during rolling or shaping and specifically, is concerned with providing guides for mills for rolling hot bars, strips, and shapes and with the provision of plugs and guides for rolling seamless tubes. Prior to my invention, although the desire and need have been known for years, no one has ever provided an alloy which possesses the very material advantage of not only wear-resistance but very definite and observable characteristics of discarding and casting 0113 any scale or hot metal which tends to deposit or weld itself to the alloy surface. When it is realized that an average bar mill guide made of ordinary standard material will take only about one thousand passes of the material being worked over the surface of the guide before the guide must be replaced or removed for resurfacing because of the heavy deposition of scale thereon, and on the other hand, the guide made of myimproved alloy is still functioning in a completely satisfactory manner after seventeen thousand passes the advantages of my invention will be more fully appreciated.

From the foregoing it will be recognized that I have provided a castable steel alloy of the sillcon-chromium-nickel-copper type having a relatively high carbon content. My improved alloy is particularly adapted to act as a guiding, shaping or forming member for hot metal and is.

characterized by outstanding wear-resistance and long life and by the very important asset of freedom from the deposition of scale or hot metal thereon.

Although in accordance with the patent I statutes, I have particularly described my invention, it will be understood that I am not to be limited thereto or thereby, but that; the scope of my invention is defined in the appended claims. 4

Iclaim:

1. An alloy comprising between .75 and about 3 per cent silicon, between about 20 and about 30 per cent chromium, between about 9 and about 15 per cent nickel, between about 3 and about 10 per cent copper, between .6 and 1. per cent carbon, and the remainder substantially all iron, said alloy being characterized by outstanding freedom from scale pickup and by particularly high wear-resistance.

2. A member adapted to engage with hot metal during the forming thereof comprising a cast steel body having an analysis including about 1 per cent silicon, about 25 per cent chromium, about 12 per cent nickel, about 3.5 per cent copper, about .65 per cent carbon, and the remainder substantially all iron, said member being characterized by wear-resistance and freedom from scale pickup.

3. An alloy comprising up to about 3 percent silicon, between about 20 and about 30 per cent chromium, between about 9 and about 15 per cent nickel, between about 3 and about 10 per cent copper, between .6 and 1. per cent carbon, and the remainder substantially all iron, said alloy being characterized by outstandingjreedom from scale pickup and by particularly high wear resistance.

JACOB TRAN'IIN, JR.