| 摘要 |
<p>The objective of the present invention is to provide a forging method realized in a way to improve 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. It is so arranged that a forged material manufactured by adding at least one kind of group 5 metals is heated to a temperature suitable for hot forging and, after forging to prescribed shape, cooled, and then held for a prescribed set time in a furnace at a tempering temperature, and is further cooled to normal temperature by natural cooling. <IMAGE></p> |
