US2463948A - Ferrous alloy - Google Patents

Description

Patented Mar. 8, 1949 FERROUS ALLOY Arthur '1. Cape, Columbus, Ohio, assignor to Coast Metals, Inc., Canton, Ohio, a corporation of Delaware No Drawing. Application May 29, 1947, Serial No. 751,473

6 Claims.

This invention relates generally to ferrous alloys, but has reference more particularly to an alloy which is especially adapted for use in the form of weld rods for hard facing purposes.

In my U. S. Patent No. 2,313,420, I have described an alloy which is used for hard facing various articles which have been subjected to wear and abrasion, but which is especially adapted for hard facing hot shears, hot working dies, soaking pit tongs, and devices for carrying or transporting hot ingots and the like. The alloy derives its usefulness from the fact that it not only has high resistance to wear and abrasion, but has high resistance, as well, to heavy and repeated impacts, that is to say, it possesses high mechanical strength. It is also resistant to chemical corrosion and to oxidation at high temperatures, has the quality of being capable of forming a sound bond with the base metal, has a high viscosity, in the molten condition, such as to permit exceedingly easy application thereof to the base metal, and is further characterized by the fact that it is hard and tough, its hardness being relatively low from the point of view of indentation hardness, except in the upper portion of its carbon range, where its hardness may be 60+ Rockwell C. The wear resistance is high at all hardnesses, which range from 40 to 60+ Rocklell C.

I have discovered that by a judicious selection of a portion of the ranges of the elements of the alloy disclosed in the aforesaid patent, and by adding to the alloy silicon in appreciable amounts, 1. e., from about 1.5% to about 4%, I am enabled to materially increase the hardness of the alloy, without having to increase the carbon content thereof. Moreover, I find that by the addition of silicon to the alloy in amounts within the range referred to, I am enabled to maintain the hardness of the alloy for any given cobalt content of the alloy.

As the cobalt content of an alloy of this character is increased, there is a tendency for the alloy to lose its austenitic state or condition, and this is likewise true when the silicon content of the alloy is increased. Moreover, as the cobalt content of the alloy is increased, the hardness of the alloy is increased, without increasing the brittleness of the alloy. Silicon likewise increases 2 the hardness of the alloy, but does increase the brittleness thereof.

Since the cobalt increases the hardness of the alloy much less rapidly than does silicon, I find that by properly balancing the proportions of cobalt and silicon, I produce highly desirable and improved properties in the alloy, with a general increase in the hardness range thereof to 50 to Rockwell C.

The weld rod, according to my improvement, is preferably made from a ferrous alloy containing from about 2.75% to about 4.25% carbon, chromium in an amount of from about 6% to about 18%, nickel in an amount of from about 3% to about 10%, molybdenum in an amount of from about 3% to about 9%, cobalt in an amount of from about 14% to about 27% and silicon in an amount of from about 1.5% to about 4%, the balance of the alloy being substantially all iron.

A preferred alloy within the foregoing range will contain about 3.5% carbon, about 16% chromium, about 5% nickel, about 7% molybdenum, about 20% cobalt, about 2% silicon, and about 53.5% iron.

I claim:

1. A ferrous alloy particularly adapted for hard facing purposes, said alloy containing carbon in the amounts from about 2.75% to about 4.25%, about 6% to about 18% chromium, about 3% to about 10% nickel, about 3% to about 9% molybdenum, about 14% to about 27% cobalt, and about 1.5% to about 4% silicon, the remainder of said alloy being substantially all iron.

2. A Weld rod for hard facing purposes, said rod comprising a ferrous alloy containing carbon in the amounts from about 2.75% to about 4.25%, about 6% to about 18% chromium, about 3% to about 10% nickel, about 3% to about 9% molybdenum, about 14% to about 27 cobalt, and about 1.5% to about 4% silicon, the remainder of said alloy being substantially all iron.

3. A heat and abrasion resistant facing comprising a ferrous alloy containing carbon in the amounts from about 2.75% to about 4.25%, about 6% to about 18% chromium, about 3% to about 10% nickel, about 3% to about 9% molybdenum, about 14% to about 27% cobalt, and about 1.5% to about 4% silicon, the remainder of said alloy being substantially all iron.

4. A ferrous alloy particularly adapted for hard facing purposes, said alloy containing about 3.5% carbon, about 16% chromium, about 5% nickel, about 7% molybdenum, about 20% cobalt and about 2% silicon, the remainder of the alloy being substantially all iron.

5. A Weld rod for hard facing purposes, said rod comprising a ferrous alloy containing about 3.5% carbon, about 16% chromium, about 5% nickel, about 7% molybdenum, about 20% cobalt and. about 2% silicon, the remainder of the alloy being substantially all iron.

6. A heat and abrasion resistant facing comprising a ferrous alloy containing about 3.5% carbon, about 16% chromium, about 5% nickel, about 7% molybdenum, about 20% cobalt and about 2% silicon, the remainder of the alloy being substantially all iron.

ARTHUR T. CAPE.

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

UNITED STATES PATENTS Number Name Date 2,208,116 Cape et al. July 16, 1940 2,313,420 Cape Mar. 9, 1943 OTHER REFERENCES