US2482382A - Corrosion resistant alloy - Google Patents

Description

Patented Sept. 20, 1949 CORROSION-RESISTANT ALLOY Ralph W. Thomas, Waukesha, Wis., assignor to Waukesha Foundry Company, Waukesha, Wis., a corporation of -Wisconsin No Drawing. Application June 12, 1947, Serial No. 754,280

2 Claims.

This invention relates to a corrosion resistant alloy.

It is a primary object of the invention to provide an alloy which is particularly suited for use in dairy equipment and other food industries in that it contains neither copper nor iron, has high tensile strength and substantial Brinell hardness, is readily cast and easily machined, and has good bearing qualities in that it moves freely upon itself or upon stainless steel without galling.

For machinery used in the handling of dairy products and other foods where sanitation isimportant, it is common to use alloys which do not corrode. Those most commonly employed are nickel alloys and stainless steel. The nickel alloys commonly have a copper base and there issome prejudice against the use of an alloy containing copper in the handling of foods. however, has the unfortunate quality of galling. That is to say, one piece cannot rub upon another without becoming roughened and seizing.

The preferred analysis of my improved alloy is as follows:

Some variation in the composition is permissible but for most satisfactory results the percentages of the ingredients should be held within the following limits:

Per cent Nickel '76-'79 Lead 3- 5 Zinc 7- 9 Tin 6.5-8.5 Manganese {1.5-2.0

An alloy made in accordance with the present Stainless steel,

invention not only contains no copper or iron, but is highly resistant to corrosion, has adequate strength, casts and machines readily and does not seize or gall when run in contact with itself or other alloys including stainless steel.

When the ingredients are mixed in approximately the stated proportions, the following data will describe its additional physical properties:

Tensile strength 50,000-60,000 p. s. i.

Yield point 40,00045,000 p. s. i. Elongation (per cent in 2 inches) 7-10 Brinell hardness (3000 kg.)-'-150 Where it is not required that the alloy be cast, the manganese may be omitted and an equal additional amount of nickel substituted. The essential ingredients are nickel, lead, zinc and tin,

the nickel representing more than three-fourths of the total.

I claim;

1. A copper and iron-free corrosion resistant and castable alloy for use in food processing machinery and consisting of 76 to 79% nickel, 7 to 9% zinc, 6.5 to 8.5% tin, 8 to 5% lead and 1.5 to 2% manganese.

2. A copper and iron-free corrosion resistant and castable alloy for use in food processing machinery and consisting of 78% nickel, 8% zinc, 8% tin, 4% lead and 2% manganese.

RALPH W. THOMAS.

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

UNITED STATES PATENT Number Name Date 1,924,244 Koster Aug. 29, 1933 40 1,988,154 Bolton et a1. Jan. 15, 1935 2,239,144 Dean 'et a1 Apr. 22, 1941