US2478724A - Ferrous base alloy for piercer points - Google Patents

Description

Patented Aug. 9, 1949 UNITED STATES ATENT OFFICE.

N'o-D'rawing. Application November 29, 1946; Serial No. 713,106

K Claims. I.

This invention relatestoan alloy and more particularly to: an alloy from: which piercing points as used in seamless tube mills can be cast.

The-principal object of: the inventionis the provision of an alloy particularly adapted for the formation of piercing points: for use in seamless tube mills, the piercing points: formed from the alloy being. characterized by their ability toform and maintain a nickel aluminum surface oxida tion forming a protective sheath on the piercing point when in operation.

A further object of the invention is the provision. of an alloy from which: piercing points canbe cast and characterized in that the piercing points formed therefrom have an unusually high resistance to picking up particles oi the metal being pierced.

A still further object of the invention is the provision of a steel alloy including effective quantities of nickel and aluminum from which: alloy piercing points for'seamlesstubemill use can ibe cast and which alloy incast form is characterizedby the ability to forma; nickel aluminum surface oxide particularly advantageous as a lubricating. sheath when the piercing point is used in a piercing operation.

It is known that in the manufactureof pipes and tubes,.piercing. points are commonly used for piercing billets to form seamless pipe and tube. The various metals from which-seamlesspipe and tube are formed ofie'r considerableresistance to the iercing points used for piercing the same and it is known. in this art that a relatively high failure ratio is common in connection with piercing points used in. piercing metalbillets in forming the seamless pipe and tube.

An ideal piercing point for the formation of seamless pipe and tube would be' capable of repeated operation without distortion of shape or picking up particles of metal being pierced. The present invention relates to an alloy which appreaches this ideal inthat arelatively soft steel alloy is disclosed. which includes relatively high quantities of nickel and aluminum and in amounts suflicient to characterize the alloy by its ability to form anickel aluminum oxidewhich forms a protective and lubricating coating on the piercing point during the piercing of a lbillet. The alloy is also capable of withstanding high thermal shock without deforming, cracking or otherwise becoming unsuitable for use, and, more importantly, is entirely free of any tendency toward picking up particles of metal being pierced.

The alloy may be efliciently handled and formed into usable piercing points as by casting,

thereby making it a very satisfactory metal for this purpose as piercing points are commonly formed by casting. The several desirable quali ties of the alloy herein disclosed make it highly desirable for use in piercing alloy steels of the high chromium and high chromium nickel types.

The alloy disclosed herein including substantial quantities of nickel and aluminum possesses scaling properties far superior to alloys hereto? fore known in the art and used for the formation of piercing points for seamless tube mill use. Thesuperiority lies primarily in the ability of the alloy to form: a nickel aluminum surface oxide and to maintain a tightly adhering nickel aluminum surface oxide over its entire surface during operation, and further in the: fact that the nickel aluminum oxide fuses and melts during a piercing operation thereby forming a desir able lubricating and protecting sheath on the piercing point.

The piercing points formed of the alloy may be of various shapes and sizes known in the art and they may comprise, for example,- a point por-- tion, a tapered body portion and the usual sleeve or neck portion of a smaller diameter than the body portion, the whole of which is adapted for simple mounting on the end of the plug bar of a seamless tube mill.

It is known that it hasb'een proposed to form steel alloys with relatively minute quantities of aluminum and it is known that such quantities of aluminum as have heretofore been incorporated in similar alloys have been entirely ineffective in the formation of a protective and lubricatingoxide on theformed' article.

In the present invention the substantial quantities of nickel and aluminum contribute to the successful formation of the protective oxide coating Whichis so important in the piercing opera tion as it enables the piercing point to maintain its proper size and shape and thereby be efficiently used" in the" formation of satisfactory seamless pipesandtubes.

The heretofore commonpractice in the formation' of alloys for piercing points has been to depend upon such alloying ingredients .as chromium and copper to" form a soft steel in an attempt to" provide a piercing point which possesses satisfactory scaling properties. Such alloys, however, have generally been incapable of repeated use as the lack of uniform scaling properties result in rapid distortion of the shape of the piercing points making the replacement necessary.

The various objects of the invention are achieved by the composition of an alloy including about .20% to 1% carbon, molybdenum i effective quantities up to 3.50%, 3% to 12% nickel, copper in effective quantities up to 7.50%, and effective amounts of aluminum up to 3%, about 25% to 1.25% silicon, about 25% to 1.25% manganese, and vanadium in efiective quantities up to 50%, and the remainder all iron. The silicon and manganese are common in steel alloys and the alloy herein disclosed includes the usual percentages of sulphur and phosphorus which are not objectionable.

The alloy shown herein may be hardened if desired by the addition of cobalt and/ or tungsten in amounts up to 5% of the alloy. The addition of the cobalt and/or tungsten in such amounts will be found to harden the alloy somewhat and affect the ability of the alloy to form the protective and lubricating nickel aluminum oxide.

A typical heat of the steel alloy of my invention possessing the several characteristics heretofore described may be seen in the following analysis: carbon 1%, molybdenum 75%, nickel 8%, copper 1.50%, aluminum 3%, silicon 1.25%, manganese 1.25%, vanadium 50%, and the remainder substantially all iron. A steel alloy formed in accordance with this invention is of such nature as to lend itself particularly well to the formation of cast articles such as piercing points which may be successfully used as integral parts in seamless tube mill equipment. It will be observed that the alloy includes relatively high quantities of nickel and aluminum. The amounts of the nickel and aluminum may be varied between the minimum effective content and about 12% for the nickel and 3% for the aluminum.

It will be seen that the relatively high percentage of the nickel and aluminum alloying elements result in the alloys ability in cast form to resist pick up of metal of the billet being pierced as it forms an eiiective continuously replacing lubricating metallic coating.

It will thus be seen that the several objects of the invention are achieved by the provision of a castable steel alloy by including relatively high percentages of nickel and aluminum. The physical characteristics 01 the alloy may be altered by heat treatment and the alloy may be hardened, if desired, by the addition of cobalt and/ or tungsten in amounts up to 5%.

Having thus described my invention, what I claim is:

1. A steel alloy having about 1% carbon, about .75% molybdenum, about 8% nickel, about 1.50% copper, about 3% aluminum, about 1.25% silicon, about 1.25% manganese, about .50% vanadium, and the remainder all iron and including the usual percentages of sulphur and phosphorus, the said alloy being capable of being cast and being characterized by the ability to form and retain a nickel aluminum oxide surface coating under severe heat and abrasion conditions.

2. A steel alloy having an analysis including between about .20% to 1% carbon, between about .75% to 3.50% molybdenum, between about 3% to 12% nickel, between about 1.50% to 7.50% copper, between about 2% to 3% aluminum, between about .25% to 1.25% silicon, between about 25% to 1.25% manganese, between about 25% to 50% vanadium, and the remainder all iron and including the usual percentages of sulphur and phosphorus, the said alloy being capable of being cast and bein characterized by the ability to form a nickel aluminum oxide and retain it under severe heat and abrasion conditions and the ability to retain its cast shape under severe heat and abrasion conditions.

3. A steel alloy having an analysis including between about .20% to 1% carbon, between about .75% to 3.50% molybdenum, between about 3% to 12% nickel, between about 1.50% to 7.50% copper, between about 2% to 3% aluminum, between about 25% to 1.25% silicon, between about 25% to 1.25% manganese, between about 25% to 50% vanadium, between about 1% to 5% cobalt and the remainder all iron and including the usual percentages of sulphur and phosphorus, the said alloy being capable of being cast and being characterized by the ability to form a nickel aluminum oxide and retain it under severe heat and abrasion conditions.

4. A steel alloy having an analysis including between about .20% to 1% carbon, between about .75% to 3.50% molybdenum, between about 3% to 12% nickel, between about 1.50% to 7.50% copper, between about 2% to 3% aluminum, between about 25% to 1.25% silicon, between about 25% to 1.25% manganese, between about 25% to 50% vanadium, between about 2% to 5% tungsten and the remainder all iron and including the usual percentages of sulphur and phosphorus, the said alloy being capable of being cast and bein characterized by the ability to form a nickel aluminum oxide and retain it under severe heat and abrasion conditions. a

5. A steel alloy having an analysis including between about .20% to 1% carbon, between about .75% to 3.50% molybdenum, between about 3% to 12% nickel, between about 1.50% to 7.50% copper, between about 2% to 3% aluminum, between about 25% to 1.25% silicon, between about 25% to 1.25% manganese, between about .25% to 50% vanadium and effective amounts of cobalt and tungsten together totaling between about 2% to 5% and the remainder all iron and including the usual percentages of sulphur and phosphorus, the said alloy being capable of being cast and being characterized by the ability to form a nickel aluminum oxide and retain it under severe heat and abrasion conditions.

JACOB TRANTIN, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date ,649,398 Fry Nov. 15, 1927 FOREIGN PATENTS Number Country Date 144,892 Austria Mar. 10, 1936