US 5,265,500 A · Method of making shock-resistant and wear-resistant tools of composite steel structure

Abstract

A method of making a shock-resistant and wear-resistant composite steel tool comprises providing a steel tool body having a working edge, and providing a working part material of nonporous wrought steel in an unhardened state which is hardenable to a hardness greater than that of the body. The working part material, in its unhardened state, is fused by welding to the working edge of the tool body while being pressed forcibly against the working edge. After the fusion step, the outer surface of the working part material is hardened to a hardness greater than that of the body of the tool, the depth of penetration of such hardening being limited to the region immediately adjoining the outer surface of the material so that the underlying region of the working part remains ductile, and the weld is normalized thereby increasing its ductility and resultant shock resistance. The method is adaptable for economical high production of saw blades, cutting bits, and other tools of composite steel structure having hardened cutting tips or other hardened working parts.

Claims24

Dependent claims

A method of making a tool comprising:

(a) providing a steel body having a plurality of spaced-apart working edges;
(b) providing an elongate rod made of non-porous wrought steel and hardenable to a hardness greater than that of said body, said rod being in an unhardened state and having an end segment;
(c) forcibly abutting said end segment of said rod, while in said unhardened state, and a first one of said working edges against each other;
(d) during step (c), applying heat to the abutting portions of said end segment and said first one of said working edges sufficient to melt and diffuse into each other both of said respective abutting portions, but insufficient to melt a major fraction of said end segment, and then cooling the diffused portions thereby fixedly fusing said end segment of said rod and said first one of said working edges together;
(e) after step (d), separating said end segment from the rest of said rod so that said end segment forms a first working part on said first one of said working edges;
(f) repeating steps (b)-(e) with respect to a second one of said working edges to form a second working part on said second one of said working edges;
and
(g) after step (e), hardening the outer surfaces of said first and second working parts to a hardness greater than that of said body.

5 more elements

Dependencies are inferred from the claim text.

Method of making shock-resistant and wear-resistant tools of composite steel structure

Life of this patent

Method of making shock-resistant and wear-resistant tools of composite steel structure

Life of this patent

Abstract

Claims24