US3362812A - Alloy steel and method - Google Patents

Description

Jan. 9, 1968 ALLOY STEEL AND METHOD OF VANDIUM ALL Filed July 6, 1965 PHYISICAL PROPERTIES OY STEELS WITH a WITHOUT CHROMIUM I25Doo- 'q nopoo- TENSILE 200": DROP To WSOOFW o STRENGTH I memo VAN.

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O.32 Cc AT T'YS United States Patent 3,362,812 ALLOY STEEL AND METHOD William R. Barber, Jr., Portland, Oreg., assignor to Esco Corporation, Portland, 0reg., a corporation of Oregon 3,362,812 Patented Jan. 9, 1968 heated to 2000 F., for two hours after which the temperature was dropped to 1750 F., for one-half hour and thereafter water quenched. Jaws produced according to this procedure had wear lives well in excess of jaws sim- Filed July 6 1965, Ser. No. 469,577 ilarly prepared, but without vanadium. On one applica- 7 Claims (CL 75 126) t1on of aws for the above-mentloned 10" X 36" Cedar Rapids crushed operated in a Western quarry, the life This invention relates to an alloy steel and method of was increased from a normal Output f 6000 t s t preparation and, more particularly, to a modified Had- 13,000 tonsfield t l f l i b i operations 10 Further investigation revealed that when using good H dfi m steel became known early in i century heat treating procedures for manganese steels (both with (see U.S. Patent 856,250). It is generally regarded as an and Witheut Chromium) y few uhdisselved carbides austenitic manganese steel (carbon about 1%, manganese can he Observed in the grain boundaries Or in the ma x l0-l4%) which, although soft in the heated treated conof the Steel- However, even When little as 25% dition, becomes surface-hardened through cold working. Vanadium is added, a Pronounced earbide pp in the This develops a particular wear life and over the years austehitic matrix the form of Small Spots When many attempts have been made to improve the wear seepieahy Observed at X)- Still further, as the P life by ddi various ll i materials cent of vanadium is increased, so also does the number I have found that wear life of austenitic manganese 0f P From this, I believe that the C inati n of steel can be materially extended by adding specific amounts chromium and Vanadium Suppresses the formation f the of vanadium and chromium to Hadfields steel, and this carbide y Promoting a more uniform Scattering of the without the need for exotic heat treatments deemed necescarbide in the matrix with the consequent development of sary in the past as art workers attempted to improve the a harder matfiX- physical characteristics of Hadfields steel. The provision other field tests ShOW h t th hromium Vanadium of this new alloy, the method of preparing the same, and alloy provides greater service life than a regular austenitic the method of developing various useful products theremanganese Stee1 'eehtaihihg Vanadium y, Without with constitute important objectives of the invention. mium Other objects may be seen in the subsequent details of To ascertain the optimum ranges of alloy materials, a this specification. series of test bars were made according to the procedure The invention is explained in conjunction with the 510- of the example, i.e., quenching from above 1700" F., and companying drawing which is a chart of various physical tested for various physical characteristics, the formulacharacteristics as a function of vanadium content of high tions and results being tabulated in Table II. From these and low chromium Hadfield steels. results, the charts of the drawing were made:

TABLE II Chro- Manga- Vana- Ten. Yld. Elong, Bed. of Hard- Charpy mium Silicon nese dium Carbon Str., Stn, in 2, Area, ness, V-Notch, Avg.

p.s.i. p.s.i. percent percent BHN it.-lbs.

0. 32 0. 45 12.95 1.14 1.12 107,750 53, 500 15 15 235 %-17 15 No.5. 1.50 0. 53 12. 85 0.54 1.22 113,750 57,500 25 24 229 38 28 33 No.6. 0.32 0.45 12.95 0.54 1.14 117,250 58,500 29 27 217 52-53% 53 No. 7. 1.75 0.53 12.85 0.37 1.24 103,000 54, 000 22 20 229 25%-27 25 No. 8- 0.32 0. 45 12.95 0.37 1.14 125,750 55,500 43 32 217 90-72 81 No. 9.. 1.85 0.54 12.95 0.17 1. 24 98,000 55,400 22 22 212 31%-35% 33 5 No.10 0.32 0. 45 12.95 0.17 1.15 124,750 54,000 53 40 207 145148% 147 No.11 (Hadfields) 0.32 0.45 12.95 1.10 115,000 43, 000 52 37 201 10215-231 212 No.12 1.50 0.38 12.85 1.30 122,500 52,000 35 32 212 44 44 This is the formulation of the example.

The invention can be best appreciated from a specific The pattern followed in making the runs 1-10 was to example which demonstrated the substantial improvement 55 compare a chromium vanadium alloy (runs 1, 3, 5, 7, and in wear life achieved through the practice of the inven- 9) with a vanadium alloy (runs 2, 4, 6, 8, and 10) of the tion. same target composition. For example in runs 1 and 2,

Example it was intended to have 1.50% vanadium (based upon the amount of vanadium added to the melt) with run 1 in- Casting l for a X Cedar Rapids efllshcluding additionally 1.50% chromium. Thus, in each of the following formulation was p oyed. runs 1, 3, 5, 7, and 9 the target was 1.50% chromium,

TABLE I but this was not precisely attained due to the impossibility Pereel'lt of accounting for the presence of unintended impurities.

Chromium 1:50 Likewise, in runs 2, 4, 6, 8 and 10, it was intended to Silicon -38 have no chromium. The analyses subsequent to casting Manganese 12.85 are those reported. Further, in the various runs, the Vanadium 0-98 amount of vanadium was decreased, i.e., for runs 1 and Carbon 2 a target of 1.50%, for runs 3 and 4 a target of 1.25%, Iron (usual impurities) Remaihdeffor runs 5 and 6 a target of 1.00%, for runs 7 and 8 a The casting procedure included adding the vanadium in target of 050%, and for runs 9 and 10 a target of 025% the form of Carvan, a high carbon ferrovanadium marketed by Union Carbide. After casting, the jaws were vanadium. Runs E and 12 correspond to the formulations used in the 18,000 lb. and 6000 lb. life jaws, respectively.

TABLE III Ingredient Useful Optimum Target 1.0-2.0 1. 3-1. 6 1. 5 15-0. 70 0. 40-0. 110 0. 50 10. -14. 0 11. 5-13 5 12. 5 25-1. 5 60-1. 05 60-1. 05 Carbon 0. 90-1. 40 1. 20-1. 35 1. 25

The vanadium target is set dependent upon the combination of physical characteristics sought, it being appreciated that the remainder is iron with the usual impurities associated therewith. In this connection, I prefer to maintain sulfur and phosphorus each below a maximum of 0.04%.

Relative to the amount of vanadium employed, I find useful percentages in the range of 0.600.80% where the casting is relatively unsupported as in the case of a crusher bowl liner. However, where ductility can be sacrificed in favor of increased wear life, as in a supported crusher jaw, the vanadium is set at the high end of the optimum range and may advantageously go to 1.25% for certain crusher jaws.

Using 0.98% vanadium in a hammermill installation resulted in an increase of 170 tons wear life (using Run 12 alloy) to 202 tons (using Run E alloy) before replacement was necessary.

In summary I have observed the following:

(1) Vanadium added in the amounts from .251.25% to an 11-14% austenitic manganese steel, with approximately 1.50% chromium, will give increased hardness to the alloy when the alloy is quenched in water in the normal manner for manganese alloys from a temperature greater than 1700 F.

(2) The preferred addition of vanadium to the base analysis of the chromium-bearing austenitic manganese steel is about .60-.80% since this providees the best combination of mechanical properties. However, if ductility can be sacrified for potential increased wear, then the vanadium may be increased to a value as high as 1.25

(3) The hardness, BHN, will increase as the vanadium content of the base alloy is increased from .25-1.25%. This increased hardness of the metal over the base alloy undoubtedly minimizes the initial wear on a part before the usual work hardening occurs.

(4) When the vanadium content is increased above 20% the yield strength of the alloy increases drastically from about 55,000 psi. to about 70,000 p.s.i. This increase in yield strength is also quite helpful in preventing the metal from flowing or spreading out, which usually happens with the regular 11-14% austenitic manganese alloy.

While in the foregoing specification, a detailed description of the invention has been set down for the purpose of illustration, many variations in the details herein given may be made by those skilled in the art without departing from the spirit and scope of the invention.

I claim:

1. An austenitic manganese steel useful in abrasive applications consisting essentially of from about 1.0% to about 2.0% chromium, from about 0.15% to about 0.70% silicon, from about 10.5% to about 14.5% manganese, from about 0.25% to about 1.5% vanadium, from about 0.90% to about 1.40% carbon with the balance iron including the usual impurities associated therewith, with a maximum of about 0.04% each of phosphorus and sulphur.

2. An austenitic manganese steel useful in abrasive applications consisting essentially of from about 1.3% to about 1.6% chromium, from about 0.040% to about 0.60% silicon, from about 11.5% to about 13.5% manganese, from about 0.60% to about 1.50% vanadium, from about 1.20% to about 1.35% carbon with the balance iron including the usual impurities associated therewith, with a maximum of about 0.04% each of phosphorus with sulphur.

3. The steel of claim 2 in which the chromium is about 1.5%, the silicon 0.50%, the manganese about 12.5% and the carbon 1.25%.

4. A method of preparing an abrasion resistant alloy steel comprising casting a mixture of from about 1.3% to about 1.6% chromium, from 0.40% to about 0.60% silicon, from about 11.5% to about 13.5% manganese, from about 1.20% to about 1.35% carbon and an amount of vanadium in the range of about 0.60% to about 1.05% along with iron and water quenching the casting from above about 1700" F., the amount of vanadium employed being in the lower end of the above-mentioned range when the casting is employed in an environment where self-support is needed and being in the higher end of the range where the casting is substantially supported in operation.

5. The method of claim 4 in which said casting is a crusher jaw.

6. The method of claim 4 in which said casting is a bowl liner.

7. The method of claim 4 in which said casting is a crusher hammer.

References Cited UNITED STATES PATENTS 436,497 9/1890 Hadfield 126 1,310,528 7/1919 Hadfield 75126 1,435,294 11/ 1922 Hadfield 75-126 2,382,651 8/1945 Nesbitt 75-126 X 2,865,740 12/1958 Heger et a1. 75123 DAVID L. RECK, Primary Examiner. P. \VEINSTEIN, Assistant Examiner.

Claims (1)

1. AN AUSTENITIC MANGANESE STEEL USEFUL IN ABRASIVE APPLICATIONS CONSISTING ESSENTIALLY OF FROM ABOUT 1.0% TO ABOUT 2.0% CHROMIUM, FROM ABOUT 0.15% TO ABOUT 0.70% SILICON, FROM ABOUT 10.5% TO ABOUT 14.5% MANGANESE, FROM ABOUT 0.25% TO ABOUT 1.5% VANADIUM, FROM ABOUT 0.90% TO ABOUT 1.40% CARBON WITH THE BALANCE IRON INCLUDING THE USUAL IMPURITIES ASSOCIATED THEREWITH, WITH A MAXIMUM OF ABOUT 0.04% EACH OF PHOSPHOROUS AND SULPHUR.

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