US2949356A

US2949356A - Ferrous alloys and articles made therefrom

Info

Publication number: US2949356A
Application number: US724503A
Authority: US
Inventors: David P Hughes; Stewart G Fletcher
Original assignee: Latrobe Steel Co
Current assignee: Latrobe Steel Co
Priority date: 1958-03-28
Filing date: 1958-03-28
Publication date: 1960-08-16
Anticipated expiration: 1977-08-16

Description

United g FERROUS ALLOYS AND ARTICLES MADE THEREFROM David P. Hughes, Ligonier Township, Westmoreland County, and Stewart G. Fletcher, Latrobe, Pa, assignors to Latrobe Steel Company, Latrobe, Pa., 21 corporation of Pennsylvania No Drawing. Filed Mar. 28, 1958, Ser. No. 724,503

8 Claims. (Cl. 75'126) This invention relates to ferrous alloys and in particular to ferrous alloys having peculiarly advantageous properties for use in hot work applications in theforming of extremely hard and diflicult to forge materials and in applications where dimension tolerance is important. There has long been a need for a steel capable of withstanding the stresses and wear problems encountered in certain hot work applications, such as dies for forging extremely hard materials, as, for example, the super alloys used for hightemperature service in jet engine parts, gas turbine parts and the like. There has also been a need for an alloy capable of withstanding the erosion encountered in extruding aluminum, brass and magnesium, as well as in die casting and other hot work applications. The steels normally used for this service have a relatively short life and consequently the die expense per forged piece is high. Not only is die cost high in such applications but the lost time and labor involved in replacing dies is a very significant pant of the cost of each part produced.

We have discovered an alloy having surprisingly advantageous properties for use in the applications mentioned hereinabove. We have found an alloy which is deep hardening and non-deforming and will maintain its form and tolerance dimensions under the extreme conditions encountered in die forging the superalloys, as well as in extruding materials such as aluminum, brass and magnesium. We have also discovered that the alloy is relatively easy to form and yet has great impact strength and resistance to dimensionchange in use.

We have found that the preferred composition of our alloy is Percent C 1.10 V 4.0 Mn 0.40 Cr 5.25 Mo 1.10

Balance substantially iron with residual impurities in ordinary amounts.

The composition of our alloy may, however, extend over a wider range and include other elements while still retaining its peculiar and highly desirable properties. In every case, however, the alloy must contain carbon, vanadium, chromium and molybdenum within the limits set out hereinafter in order to retain these desirable and peculiar properties. The broader composition may fall within the limits of ice Balance substantially iron with residual impurities in ordinary amounts, in which alloy the vanadium shall appear in amounts within the foregoing limits that vanadium 1 Carbon T shallbe with the limits .18 to .86%.

We have found that when the chromium or molybdenum concentration isin the lower end of the range set out above, it is preferable that the manganese concentration approach the upper end of the limits set out herein-above in order that the resulting alloy have the most desirable properties. The machining properties of the alloy are varied by varying the sulphur within the range set out hereinabove, the higher sulphur content promot ing better machining as well as reducing the cost of forming dies for the various purposes to which this alloy may be applied.

While we have given certain limits with respect to the concentration of tungsten and nickel which may be present, their presence is not necessary and in our preferred composition these elements are absent. However, their presence is optional and may be desirable for certain purposes within the ranges set out above.

Inorder to illustrate the peculiar adaptability of the present alloy for use as hot working dies for forging extremely hard and diflicult materials, several dies were formed of the preferred composition. These dieswere used alongside dies made from conventional alloys. The dies were used to forge turbine blades from high alloy compositions, as, for example, Nimonic alloy. The dies were operated until a satisfactory product no longer could be obtained from the dies. It was found that the dies made of the composition of the present invention produced more than four times as many pieces, as the conventional alloys. A die made of the alloy of the present invention produced approximately eight-thousand pieces from Nimonic 80 alloy, whereasa conventional die produced only about two-thousand pieces. Other comparative tests of the same type using other high alloy materials showed a comparative life of four to ten times greater in dies made from the present alloy as compared with dies made from conventional alloys.

It is evident that the advantage of the present alloy as respects to die cost alone is very great. However, the true economic importance of this result becomes more apparent when it is realized that the cost in labor and lost time in changing dies is almost as great as the cost of the dies themselves so that an increase in die life of four times actually represents a saving of approximately eight times in over-all production costs. This is a very significant saving in the cost of producing high temperature super-alloy parts for turbines, jet engine parts and the like.

While we have illustrated and described certain preferred embodiments of my invention, it will be understood that the invention may be otherwise embodied within the scope of the following claims.

We claim:

1. An alloy adapted for forming metals at high temperatures comprising about 0. 65% to about 3.0% carbon, about 3.0% to about 10.0% vanadium, less than about 2% manganese, about 3.0% to about 8.0% chromium, up to about 2% tungsten, about 0.50% to 3.0% molybdenum, up to about 2% silicon, up to about 3% nickel, up to about 0.25% sulphur and the balance substantially iron with residual impurities in ordinary amounts in.

vanadium 1 is within the limits of about 0.18% to about 0.86%.

2. An alloy adapted for hot working applications comprising about 1.10% carbon, about 4.0% vanadium, about 0.4% manganese, about 5.25% chromium, about 1.10% molybdenum, about 1.0% silicon and the balance substantially iron with residual impurities in ordinary amounts.

3. An article for forming metals at high temperatures formed from a steel alloy comprising about .65% to about 3.0% carbon, about 3.0% to about 10.0% vanadium, less than about 2% manganese, about 3.0% to about 8.0% chromium, up to about 2% tungsten, about .50% to 3.0% molybdenum, up to about 2% silicon, up to about 3% nickel, up to about 0.25 sulphur and the balance substantially iron 'with residual impurities in ordinary amounts in which alloy the vanadium appears in amounts within the foregoing limits such that the Carbon vanadium- 1 4.2

is within the limits of about 0.18% to about 0.86%, said article being characterized by high resistance to deformation at elevated temperatures and deep air hardening.

4. A die formed from a steel alloy comprising about "165% to about 3.0% carbon, about 3.0% to about 10.0% vanadium, less than about 2% manganese, about 3.0% to about 8.0% chromium, up to about 2% tungsten, about .50% to 3.0% molybdenum, up to about 2% silicon, up to about 3% nickel, up to about 0.25% sulphur and the balance substantially iron with residual impurities in ordinary amounts in which alloy the vanadium appears in amounts within the foregoing limits such that the Carbonvanadium-1 Carbon 4 about 1.0% silicon and the balance substantially iron with residual impurities in ordinary amounts, said article being characterized by high resistance to deformation at elevated temperatures and deep air hardening.

5 6. A die for forming metals at high temperatures formed from a steel alloy comprising about 1.10% carbon, about 4.0%vanadium, about 0.4% manganese, about 5.25% chromium, about 1.10% molybdenum,

about 1.0% silicon and the balance substantially iron 'With residual impurities in ordinary amounts, said die being characterized by high resistance to deformation at elevated temperatures and deep air hardening.

7. An alloy adapted for forming metals at high temperatures comprising about 0.65% to about 1.4% carbon, about 3.0% to about 10.0% vanadium, less than about 2% manganese, about 3.0% to about 8.0% chromium, up to about 2% tungsten, about 0.50% to 3.0% molybdenum, up to about 2% silicon, up to about 3% nickel, up to about 0.25% sulphur and the balance substantially iron with residual impurities in ordinary amounts in which alloy the vanadium appears in amounts within the foregoing limits such that the i vanadium 1 Carbon -T is within the limits of about 0.18% to about 0.86%.

8. An article for forming metals at high temperatures formed from a steel alloy comprising about .65% to about 1.4% carbon, about 3.0% to about 10.0% vanadium, less than about 2% manganese, about 3.0% to about 8.0% chromium, up to about 2% tungsten, about .50% to 3.0% molybdenum, up to about 2% silicon, up to about 3% nickel, up to about 0.25 sulphur and the 35 balance substantially iron with residual impurities in ordinary amounts in which alloy the vanadium appears in amounts within the foregoing limits such that the article being characterized by high resistance to deformation at elevated temperatures and deep air hardening.

Carbon References Cited in the file of this patent UNITED STATES PATENTS Luerssen et al. Aug. 8, 1944 Giles Nov. 13, 1951

Claims

1. AN ALLOY ADAPTED FOR FORMING METALS AT HIGH TEMPERATURES COMPRISING ABOUT 0.65% TO ABOUT 3.0% CARBON, ABOUT 3.0% TO ABOUT 10.0% VANADIUM, LESS THAN ABOUT 2% MANAGNESE, ABOUT 3.0% TO ABOUT 8.0% CHROMIUM, UP TO ABOUT 2% TUNGSTEN, ABOUT 0.50% TO 3.0% MOLYBDENUM, UP TO ABOUT 2 SILICON, UP TO ABOUT 3% NICKEL, UP TO ABOUT 0.25% SULPHUR AND THE BALANCE SUBSTANTIALLY IRON WITH RESIDUAL IMPURITIES IN ORDINARY AMOUNTS IN WHICH ALLOY THE VANADIUM APPEARS IN AMOUNTS WITHIN THE FOREGOING LIMITS SUCH THAT THE