US3563731A

US3563731A - Cobalt-base alloys containing chromium,carbon,tungsten and nickel

Info

Publication number: US3563731A
Application number: US845582A
Authority: US
Inventors: Arthur T Cape
Original assignee: Coast Metals Inc
Current assignee: Coast Metals Inc
Priority date: 1969-07-28
Filing date: 1969-07-28
Publication date: 1971-02-16
Anticipated expiration: 1988-02-16

Abstract

A COBALT-BASE ALLOY CONTAINING CHROMIUM, CARBON, TUNGSTEN AND NICKEL IS PRODUCED, FOR USE IN JOINING HIGH TEMPERATURE ALLOYS. THE ALLOY HAS A RELATIVELY HIGH CARBON CONTENT AND A RELATIVELY LOW NICKEL CONTENT, SUCH THAT A SUBSTANTIAL INCREASE IN HARDNESS IS EFFECTED WITHOUT SACRIFICE IN TOUGHNESS AND DUCTILITY, AND A BETTER YIELD OF RODS IS OBTAINED WHEN THE ALLOY IS GROUND INTO WELD RODS.

Description

United States Patent Olhce Patented Feb. 16, 1971 3 563 731 COBALT-BASE ALLoYs CONTAINING CHRO- MIUM, CARBON, TUNGSTEN AND NICKEL Arthur T. Cape, Monterey, Califi, assignor to Coast Metals, Inc., Little Ferry, N.J., a corporation of Dela- Ware N Drawing. Filed July 28, 1969, Ser. No. 845,582

1 Int. Cl. C220 1 9/ 00 US. Cl. 75171 2 Claims ABSTRACT OF THE DISCLOSURE In the U8. Pat. No. 3,265,494, of James F. Baldwin and Arthur T. Cape, an alloy consisting essentially of chromium, tungsten, nickel and cobalt is described, which is especially useful for high temperature applications, such, for example, as joining areas of Waspalloy jet engine turbine blades. A particular feature of the alloy was its ductility and freedom from brittleness which were such that the alloy, when made into weld rods, could be passed through a centerless grinder without shattering.

I have found that by increasing the carbon content of such an alloy substantially, and lowering the nickel content to a narrow range below 4%, that an alloy of this type is produced, which is characterized by a desired substantial increase in hardness, without any sacrifice in toughness and ductility, and by the fact that the alloy, when ground in a centerless grinder, to form Weld rods, can be ground down to very small diameters ranging from .0625" to .037".

The hardness, in particular, is increased from hardness of 45-48 Rockwell C, in the case of the alloy of the aforesaid patent, to a hardness range of 59-65 Rockwell C, in the case of the present alloy.

Alloys made in accordance with this invention have the following analysis range, with a preferred alloy of the analysis indicated, the figures being percentages by weight.

Range, percent Preferred,

percent 1 Maximum.

Alloys within the aforesaid ranges have, as stated, a Rockwell C hardness of 59-65, and can be ground into weld rods, of diameters of .0625".037, with an increased yield of such rods, in comparison with those of the aforesaid patent.

Having thus described my invention, I claim:

1. An alloy especially adapted for use as a Welding material at high temperatures, said alloy consisting of carbon 2.5 to 3.0%, chromium 26 to 30%, nickel 3.0 to 3.90%, tungsten 18 to 21%, .005 to .1% boron, O to 1% silicon, .75 to 1.25% vanadium, O to 1% manganese, 0 to 3% iron, and the balance essentially all cobalt.

2. 'An alloy especially adapted for use as a Welding material at high temperatures, said alloy consisting of about 2.87% carbon, about 28.60% chromium, about 3.50% nickel, about 19.25% tungsten, about .05% boron, about .50% silicon, about 1.0% vanadium, about .4% iron, about 0.1% manganese, and about 43.73% cobalt.

References Cited UNITED STATES PATENTS 3,265,494 8/1966 Baldwin et a1. 171

RICHARD O. DEAN, Primary Examiner