US2147121A - Alloy compositions and articles made therefrom - Google Patents

Description

a the percentages given, viz.:

Patented Feb. 14, 1939 ALLOY COMPOSITIONS AND ARTICLE MADE THEREFROM Joseph V. Emmons, Shaker Heights, Ohio, assignor to The Cleveland Twist Drill Company, Cleveland, Ohio, a corporation of Ohio I No Drawing. Application August 18, 1938, Serial No. 225,575

10 Claims. (01. 75-126) This invention relates, as indicated, to alloy compositions and articles made therefrom, and relates more particularly to ferrous alloys of the type in which molybdenum and tungsten are important alloying elements.

In my prior Patent No. 1,937,334, dated November 28, 1933, there are disclosed alloy compositions of the class in which molybdenum and tungsten are principal alloying elements and in which molybdenum and tungsten bear to each other a certain defined proportional relationship. The present invention is, in effect, an extension of the teaching in this prior patent,'particularly with respect to variations in the amount of carbon in the alloy composition.

It is among ,the objects of my invention to provide alloy compositions of the same general character as those disclosed in my above identified prior patent but-which, due to variations in the amount ofcarbon are better suited for certain purposes than the compositions defined in such prior patent.

Other objects of my invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the stituting, however, but a few of the various forms in which the principle of the invention may be used.

My invention may be, as above indicated, stated in general terms as comprising. the discovery that certain variations in the composition or compositions disclosed in my aforementioned prior patent result in alloys, particularly useful for certain purposes; more specifically, the present invention relates to variations in the amount of carbon present in the alloy composition.

In accordance'with my present invention, an alloy may contain the following elements within;

Per cent Carbon 1.35 to 2.25 Manganese None to 2.00 Silicon An effective amount up to 3.00 Chromium None to 15.00 Tungsten 0.20 to 6.00 V n i None to 5.00 Molybdenum 0.60 to 15.00

' Coba None to 16.00

the remainder being substantially iron, together with such other alloying ingredients and impurities as are sometimes found in this type of alloy compositions.

A somewhat narrower range of percentages within which the various alloying elements may be present in compositions in accordance with my invention is as follows: v

- Per cent Carbonm; 1.35 to 2.00 Manganese 0.05 to 1.00 Silicon 0.10 to 0.75 Chromium 0.20% 10.00 Tungsten 0.50 to 4.00 Vanadium 0.20 to 3.50 Molybdenum 4.00 to 12.50 Cobalt 1.00 to 12.00

the remainder being substantially iron together with such other alloying elements and impurities as are sometimes found in compositions of the character to which this invention relates.

A further and still narrower range of percentages within which the various elements may be present in alloys in accordance with the present invention is as follows:

Per cent Carbon 1.35170! 1.60 Manganese 0.09 to 0.50 Silicon 0.10 to 0.45 Chromium 2.50 to 5.00 Tungsten 1.00 to 2.50 Vanadium 0.60 to 2.50 Molybdenum 6.00 to 15.00

the remainder being substantially iron together with such other alloying elements and impurities as aresometimes found in compositions of the character to which this invention relates.

Specific examples of alloy compositions embodying my invention are as follows, viz.:-

Example 0 Mn Si Cr W V M'o Cobalt;

the remainder being substantially iron, together with such other alloying elements and impurities stand certain types of wear in dies, cutting tools,

and machine parts. Such steels also have, in general, a higher resistance to softening at temperatures at the top of or higher than the normal tempering range than do the steels having below 1.30% carbon.

It will be observed thattl je foregoing specific examples may be divided into three classes, as follows, viz.:--

Class A, comprising specific Examples 1, 2, 3,

and 4, characterized by a relatively high alloy content; I

Class B, comprising specific Examples 5, 6 and 7, characterized by a relatively low alloy content; and

Class C, comprising specific Examples 8 and 9,

characterized by an intermediate alloy content and more particularly by a high chromium content.

The following tables are given as the ranges of percentages within which the various elements may be present in the alloys of the respective the remainder being substantially iron, together with such other alloying elements and impurities as are sometimes found in this typeof alloy compositions.

-C'lass B 1 Per cent Carbon 1.35-1.80 Manganese .09-1L00 Silicon- .10-0.45 Chromium .2o-s.oo Tungsten s .20-1.20 Vanadium None-1.00 Molybdenum .60-3.00 the remainder being substantially iron, together withrsuch other alloying elements and impurities as are sometimes found in this type of alloy compositions.

Class C' Per cent Carbon g 1.50- 2.25 Manganese; 1 .09- 1.00 Silicon 1(). 1.00 Chromium 700-1500 Tungsten .20- 2.00 Vanadium -1 None- 2.00 Molybdenum 1.00- 5.00

the remainder being substantially iron, together with such other alloying elements and impurities as are sometimes found in this type of alloy compositions.

' -ly described .as follows:

75 or parts subject to severe wear. Lathe tools made The characteristics of each class may be brief- Class 4 representedby Examples 1, 2, 3 and 4 comprises high speed steels of high alloy content.:,'1'hey are characterized by great resistance to grain growth at high hardening temperatures.

Example 2, when hardened at 2325" F. and tempered at 1040 F. had a Rockwell hardness of C68. Its microstructure shows unusual quantitles of hard carbides and offers great resistance "tocertain forms of abrasive action. This struc- 'ture, in connection with the great hardness it is capable of attaining, fits this steel for use in itools from Example 2, when compared with lathe tools made from 18-4-1 high speed steel, had a performance from 38% to 51% better.

The addition of carbon from 1.35% to 2.25% in the case of steels having a high alloy content such as those of Class A gives the steels adequate hardness to function as high speed cutting tools to a degree which would'not be possessed by these steels if their carbon content was below For cutting tools required to withstand the most severe service, the addition of cobalt to this class of steels will be found to be desirable.

Class B represented by Examples 5, 6, '7 com- ,prises a low.alloy type of'tool steel which is superior to carbon tool steels for many purposes, They are generally hardened by quenching in oil. The permissible hardening range is broad, extending from about 1500 F. to about 1960" F. When hardened in the lower part of this hardening range and tempered from none to about.

350 F., exceptionally high hardnesses of Rockwell C68 and over have been observed. When hardened in the upper part of the hardening range, this class of steels develops'a secondary hardness which will appear, with hardening temperature of about 1800 F., at a tempering temperature-of about 500 F., while with a hardening temperature of about 1960 F. it will appear at a tempering temperature of, about 940 F. With intermediate hardening temperatures, 1870 F. to 1920 F., the secondary hardness may be best developed at tempering temperature about 640 F. These secondary hardnesses are usually within the range of Rockwell'S57 to C63. This secondary hardness, stable athigh tempering temperatures, makes possible tools and wearing parts which will maintain their hardness at operating temperatures almost as high as the temperingtemperatures used to produce it. Tools such as drills made in this manner have shown a cutting performance far superior to that of tools made of carbon tool steel.

Class C typified by Examples 8 and 9 contains a high chromium content together with the molybdenum and tungsten. It is characterized by a microstructure having many free carbide par- .ticles. This givessurfaces made from this steel great resistance to certain types of wear. In particular, hardened steels of this class will show materially greater resistance to tempering than steels containing high carbon and high chromium without the molybdenum and tungsten in the proportions disclosed.

Example 9 in particular has an exceptionally broad, useful hardening range from about 1550 F. to about 2150 F. It is generally preferable to quench in oil although for special purposes either water, air or quenching baths at elevated temperatures may be used. With a hardening temperature of 1785 F. a primary hardness of Rockwellv C67 was obtained. Witha hardening temperature of 1930". F. and a tempering temperature of 1040 F., a secondary hardness of Rockwell 061 was obtained. With a hardening temperature of 2150 F. and a tempering temperature of 1140 F., a Rockwell hardness of C59 was obtained. It has also been observed that when hardened at temperatures of 2000" F. or higher and not tempered, Example 8 is not attracted by a magnet, showing that it is in an austenitic condition. .This austenite is readily converted to martensite by tempering. In general, Example 8' shows a greater resistance to grain growth at high hardening temperatures. a

. tungsten in amounts from 10% higher secondary hardness and a higher resistance to tempering at temperatures over 1100 F. than comparable high carbon high-chromium. steels of the prior art which did not contain the molybdenum and tungsten.

These properties are believed to give this class a broad usefulness in the field of dies, cutting tools and wear-resisting parts. It has also been observed that Example 9, when in the-austenitic condition, shows great resistance to acid. attack. It is believed that this ugeiulness where strong and abrasion-resisting materials are required to also withstand oxidation at high temperatures or corrosion.

As previously indicated, compositions of therange of from to 40%, above referred to,

may be conveniently divided into the following groups, viz.:-5% to 16%, 16% to 25% and 25% nese, chromium,

. Attention is directed to the fact that certain 0.. the examples included in the foregoing descrlption of my invention may be readily nitrided.

As'is well known to those familiar-with the art, any specification for a particular alloy composition must permit of certain variations due tothe fact that in making up the composition it is extremely diifieult, if not impossible, to commercially produce a composition exactly like a given specification. It is to be understood, therefore, that throughout the description and claims, where I have used figures .to denote definite amounts and ranges, such amounts and ranges are to be construed to include the range of variations usually permissible in making up alloy compositions to given specifications.

It is understood that in the compositions specified herein, minor amounts of other alloying elements such as titanium, tantalum. columbium. uranium, boron, zirconium, copper, aluminum. etc., as well as minor amounts of impurities such as sulphur, phosphorus, arsenic, tin, etc., may be included and when the phrase the remainder being substantially all iron" is used it is intended to include minor amounts of such elements which, for example, may find their way into the composition by being present in the raw materials such as scrap used in making up the composition or'which may be intentionally added in the amounts and for the purposes for which such elements are sometimes employed in ferrous alloy compositions.

It should be noted that where the term none" is used to denote the absence of manganese, chromium, vanadium and cobalt. the construction to be placed upon this term is a commercial absence of the elements in question. Mangavanadium and cobalt may be considered as commercially absent it they are present in amounts less than 0.05%.

This application is a continuation in part of my copending application Serial No. 741,532, filed. August 27,1934. A

Other modes of applying the principle of my class may have a field of invention may be employed instead of those explained, change being made as regards the materials employed, provided the. ingredients stated by any of the following claims or the equivalent of such stated ingredients be employed.

I, therefore, particularly point out and distinctly claim as my invention:--

1. A ferrous alloy composition comprising Per cent Carbon About 1.35 to about 2.25 Silicon From an efiective amt. to about Molybdenum From 0.60 to, about 15.00

Vanadium- From an eifective amt. to about 5.00 Chromium From an eflecti-ve amt. to about 15.00

tungsten from. 5.00% to 40.00% of the amount of molybdenum present and the remainder being substantially all iron.

2. A ferrous alloy composition comprising Per cent Carbon About 1.35 to about 1.60 Silicon About .55 to about 3.00 Molybdenum. About 0.60 to about 15.00

Vanadium- From an effective amt. to about 5.00 Chromium From an effective amt. to about 15.00

tungsten from 5.00% to 40.00% of the amount of molybdenum present and the remainder being substantially all iron.

3. A ferrous alloy composition comprising Per cent Carbon About 1.35 to about 1.60 Silicon About 0.10 to about 0.45

-- Molybdenum. About 6.00 to about 15.00 Tungsten About 1200 to about 2.50 Vanadium... About 0.60 to about 2.50 Chromium. About 2.50 to about 5.00

the amount of tungsten actually present being from 5.00% to 40.00% of the amount of molybdenum present and the remainder being substantially all iron.

4. A ferrous alloy composition comprising Per cent Carbon About 1.35 to about 1.80 Silicon About 0.10 to about 0.45 Molybdenum About 0.60 to about 3.00 Tungsten About 0.20 to about 1.20 Chromium About 0.20 to about 3.00

Vanadium.From an effective amt. to about 1.00 the amount of tungsten actually present being from 5.00% to 40.00% of the amount of molybdenum present and the remainder being substantially all iron.

5. A ferrous alloy composition comprising Per cent Carbon About 1.50 to about 2.25 Silicon About 0.10 to about 1.00 Molybdenum About 1.00 to about 5.00 Tungsten About 0.20 to about 2.00 Chromium About 7.00 to about 15.00

Vanadiumjrom an effective amt. to about 2.00

the amount of tungsten actually present being from 5.00% to 40.00% of the amount oi molybdenum present and the remainder being substan- Chromium and the remainder being substantially all iron.

7. A ferrous alloy composition comprising Per cent Carbon -1 1.96 Silicon 0.43 Molybdenum 1.49 Tungsten"; 0.46 Vanadium 0.33 Chromium 8.00

and the remainder being substantially all iron.

8. A ferrous alloy composition comprising Per cent Carbon 1.35 Silicon 0.45

Molybdenum 2.07 Tungsten 0.5 1 Vanadium 0.32 Chromium 1.08

and the remainder being substantially all iron.

CERTIFICATE OF CORRECTION.

Patent No. 2,lh.7,l2l.

. Per cent Carbon About 1.35 to about 2.25 Silicon"- From: an effective amt. to about 3.00 Molybdenum From 0.60 to about 15.00

Vanadium From an effective amt. to about 5.00 Chromiumlrom an efiective amt. to about 15.00

tungsten from 25.00% to 40.00% of the amount of molybdenum present and the remainder being substantially all iron.

' JOSEPH V. EMMONS.

February 111, 1959 JOSEPH V. EMMONS.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, second column,

line 55, for "S57" read C57; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 21st day of March. A. D. 1959.

(Seal) Henry Van Arsdale Acting Commissioner of Patents.