US3627515A - Engine component steel containing small amounts of chromium and nickel - Google Patents

Abstract

AN INTERNAL COMBUSTION ENGINE COMPONENT HAVING AT LEAST THE BEARING SURFACE OF A HARDENABLE FERROUS ALLOY CONTAINING BOTH TITANIUM AND TUNGSTEN IN CONTROLLED RANGES GIVING SYNERGISTIC RESULTS IN WEARABILITY.

Description

United States Patent Ofice ENGINE COMPONENT STEEL CONTAINING SMALL AMOUNTS OF CHROMIUM AND NICKEL Kenneth E. Kueny, North Muskegon, Mich., assignor to Johnson Products Inc., Muskegon, Mich. No Drawing. Filed May 7, 1970, Ser. No. 37,015 Int. Cl. C22c 39/20 US. Cl. 75-128 5 Claims ABSTRACT OF THE DISCLOSURE An internal combustion engine component having at least the bearing surface of a hardenable ferrous alloy containing both titanium and tungsten in controlled ranges giving synergistic results in wearability.

BACKGROUND OF THE INVENTION This invention relates to engine components, and more particularly to engine components having greatly superior wearability.

In my Patent 3,370,941 is disclosed a tungsten containing cast iron alloy having beneficial hardness qualities. This alloy has demonstrated markedly better characteristics compared to conventional hardenable iron, for high compression engines.

Consequently, this material has proven to be a significant advance in the auto industry.

SUMMARY OF THE INVENTION Subsequent to the invention in the above noted patent, it was discovered that by the addition of a controlled amount of titanium to the novel tungsten alloy, with modification of this alloy to controlled component ranges, unique synergistic wearabality results occur. The novel alloy is extremely effective in high compression engines. Its wearability is unexpectedly three times greater than even the alloy of the above mentioned patent, hence many times greater than conventional hardenable iron. Although my Patent 3,472,651 teaches of a titanium containing hardenable iron, it was never guessed that the controlled incorporation of titanium and tungsten would have the synergistic results experienced.

It therefore is an object of this invention to provide an engine component material having highly unusual wearability, many times greater than hardenable iron, yet capable of being readily founded by casting into sand molds, shell molds, CO molds or permanent molds. It has been found particularly useful for components such as tappets and camshafts, but can be used for others where friction wear is a problem.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Basically the engine component alloy is a hardenable iron composition as follows:

Element: Percent by weight Total carbon 3.00-3.60 Silicon 2.00-3.00 Manganese 0.70-1.25 Phosphorous a 0.20 max. Sulfur a 0.10 max. Nickel 0.15-0.70 Chromium 0.40-l.25 Molybdenum 0 -070 Titanium 0 10-100 Tungsten O.50-l0.0 Iron Balance Impurity.

Patented Dec. 14, 1971 The phosphorous and sulfur elements are normal impurities which are almost invariably present in these ferrous alloys. They are not required.

The controlled percentages of titanium and tungsten are essential to the composition. It is by carefully controlling the composition to this range that the surprisingly high wearability results.

A preferred specific composition in the above noted range is as follows:

Element: Percent by weight Total carbon 3.50 Silicon 2.42 Manganese 0.82 Phosphorous a 0.09 Sulfur a 0.03 Nickel 0.21 Chromium 0.72 Molybdenum 0.34 Titanium 0.19 Tungsten 3.20 Iron Balance Impurity.

This composition, when tested for tappets and camshafts, for example, showed an excellent initial and retained hardness and demonstrated a wearability unexpectedly three times greater than the tungsten bearing hardenable iron alloy in the above identified Patent 3,370,941. Since such tungsten alloy has hardness and wearability characteristics markedly greater than conventional hardenable iron alloys, the value of these present synergistic results are clearly evident. The material retains its hardness at greatly elevated temperatures, even up to about 900 F.

Preferably the complete engine component, e.g. tappet, camshaft, rocker arm, or other, is formed of the novel alloy, but at least the bearing surfaces thereof are of the novel alloy.

The components may be cast by normal casting techniques wherein the material is melted by any standard melting method, then poured into suitable molds, such as sand molds, shell molds, carbon dioxide molds, or permanent molds, with or without chill plates as of carbon. It may be hardened by normal heat training techniques such as those conventionally used on hardenable iron for such components, a typical heat treatment including heating to 1575 F., holding forthirty minutes, then quenching in oil. It is conceivable that minor variations may be made within the concept presented, with the invent-ion being limited only by the scope of the appended claims and the reasonable equivalents thereto.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows.

1. An internal combustion engine component comprising a body having at least a bearing surface of a hardenable ferrous alloy consisting essentially of the following composition:

phorous impurities) Balance 2. The component of claim 1 being a tappet.

3. The component in claim 1 being a camshaft.

4. The component in claim 1 being a rocker arm.

5. The component in claim 1 substantially of the following composition:

Element: Percent by weight Carbon 3.50 Silicon 2.42 Manganese 0.82 Nickel 0.21

Chromium 0.72

Molybdenum 0.34 Titanium 3.20

Tungsten 0.19

Iron (plus minor sulfur and phosphorous impurities) Balance References Cited UNITED STATES PATENTS 10 HYLAND BIZOT, Primary Examiner PMOSO STATES PATENT @FFTCE @EETTTTQATE QT @QRREQTTGN- Patent Non 3,627,515 Dated December 14, 1971 n i l Kenneth E. Kueny It ceriii'iwji that error appears in the above-identified patent e124; than; said Letters Patent are hereby corrected as shown below:

Claim 5, line 11; delete 5;:20 and insert "0.19"

line 12; delete 0.19 and insert "3.20".

Signed and sealed this 15th day of January 197M.

( SEAL) Attest:

EDWARD M. FLEI'CHER,JR. RENE Da TEG-TMEYER Attest'ing Officer Acting Commissioner of Patents