US 6,743,311 B2 · Forging method

Abstract

The objective of the present invention is to provide a forging method that improves workability in machining, by turning the metallographical structure of products subject to impact load to a fine ferrite-perlite structure, without adopting the method of quenching and tempering, to obtain, as strength, a yield point (YP value) exceeding that obtained by the method of quenching and tempering, and making the tensile strength (TS) smaller compared with the method of quenching and tempering. A material to be forged has at least one kind of group 5 metal added thereto and is heated to a temperature suitable for hot forging. After forging to prescribed shape, cooling, and holding for a prescribed set time in a furnace at a tempering temperature, the material is further cooled to normal temperature by natural cooling.

Claims2

Dependent claims

A method of forging a material, said method comprising:

adding a second material to steel to obtain a third material, the second material comprising at least one metal from the group consisting of group VB metals;
heating the third material to a temperature in a range of 1150-1250° C.;
forging the heated third material to a prescribed shape;
cooling the forged third material;
holding the cooled forged third material in a tempering temperature area of a furnace at a temperature in a range of 500-700° C.;
and
cooling the cooled forged material to a normal temperature by natural cooling, so that carbon and nitrides that include the second material precipitate on the steel.

4 more elements

Dependencies are inferred from the claim text.

Forging method

Life of this patent

Forging method

Life of this patent

Abstract

Claims2