US2081394A - Weld rod - Google Patents

Description

Patented May 25, 1937 WELD ROD Anthony G. de Golyer, New York, N. Y" assignor to Vulcan Alloys Corporation, a corporation of Delaware No Drawing. Application October 14, 1936, Serial No. 105,515

1 Claim.

This 'invention relates to a new alloy steel and relates particularly to an alloy steel containing molybdenum, tungsten, chromium, cobalt, manganese and boron, in the form of weld rod for the 5 production of welded surfaces or sections characterized by relatively high degree of hardness, resistance to abrasion and resistance to deformation under impact.

In many industrial operations it is desirable to apply a facing or inlay of hard wear resistant metal to parts of machinery or other equipment exposed to excessive abrasion or impact. Various alloys and materials have been proposed for this purpose. All'of such heretofore suggested compositions contain high percentages of alloy elements, together with at least 1% or more,

carbon. In general, weld metal deposited with such compositions may have high hardness, i. e.

approximately 400 to 500 Brinell hardness numbers, but all such deposits are relatively brittle chiefly by reason of the high carbon content, and, consequently are not-suitable for use on surfaces exposed to impact or shock as well as abrasion.

The object of the present invention is to provide an alloy which may be 'readily'deposited by fusion welding, and which produces weld metal having relatively high strength, high resistance to deformation under impact and relatively high hardmess.

I have found that an alloy composed of molybdenum 7% to 17%, tungsten 5% to 15%, chromium 3% to 9%, cobalt 3% to 10%, boron 0.75% to 2.25%, carbon 0.20% to approximately 1%, manganese 0.30% to 5% and the remainder substantially iron, possess high hardness, high strength and is extremely resistant to deformation under impact, when deposited by means of welding. The present alloy is particularly adapted for electric arc welding. Metal so deposited has a hardness of from 625 to 750 BrinelLdepending, in part, upon the composition of the base metal and the ratio of dilution. Weld deposits of the alloy which have been subjected to cold work or hardness.

A distinct advantage of the present alloy is that it may be readily welded on steel of any carbon content and'virtually all types of alloy steels, including 14% manganese steel. The combination of physical properties and characteristics possessed by this alloy render it particularly valuable for facing or rebuilding surfaces of equipment exposed to extreme conditions of abrasive wear and impact.

p The essential components of my alloy are molybdenum, tungsten, chromium, cobalt, boron, carbon, manganese and iron. The principal impact usually show an appreciable increase in constituent is iron. Extensive experiments which I have made indicateconclusively that the.

alloy possesses the desired combination of high hardness and high resistance to failure under impact only when the essential components are present within the following percentages: molybdenum 7% to 17%, tungsten 5% to 15%, chromium 3% to 9%, cobalt 3% to 10%, boron 0.75% to 2.25%, carbon 0.20% to approximately 1%, and manganese 0.30% to 5%, the remainder being principally iron. .It will be understood that small amounts of silicon will be present as an impurity incidental to manufacture. Also, minor amounts of sulphur, phosphorus and other impurities commonly found in alloy steels will usually be present as incidental impurities. The amounts ofallof such impurities should be restricted to maximum limits ordinarily prescribed for alloy steels.

One distinctive advantage of the present alloy-is that it makes possible the production, by welding, of deposits having high hardness without the presence of large amounts of carbon, 1. e., greater than approximately 1%, which render alloys of molybdenum, tungsten and iron extremely brittle. I have found that the presence of appreciable amounts of boron in the alloy results in the production of weld deposits which are not only hard, e. g., 650 Brinell or higher, but which are also remarkably tough, i. e., resistant to failure under impact.

As specific examples, alloys within the scope of the present invention which I have found to be particularly suitable for deposition by welding are the following: molybdenum 7%, tungsten 9%, chromium 4%, cobalt 9%, boron 1.10%, carbon 0.45%, manganese 2.10% and balance substantially iron; molybdenum 11%, tungsten 9%, chromium 5%, cobalt 6%, boron 1.40%, carbon 0.55%, manganese 2.85% and the balance substantially iron.

I wish to explain that in the present alloy molybdenum and tungsten are not equivalents, but that each of these elements performs certain definite functions, and in order to produce an alloy having in combination the desired physical properties and characteristics both molybdenum and tungsten must be present within the limits specified herein.

I claim:

A weld rod comprising a metallic composition containing molybdenum 7% to 17%, tungsten 5% to 15%, chromium 3% to 9%, cobalt 3% to 10%, boron 0.75% to 2.25%, carbon 0.20% to 1%, manganese 0.30% to 5%, and the remainder substantially iron..

ANTHONY (1'. DE GOLYER.