METHOD FOR FORGING A CRANK THROW, METHOD FOR MANUFACTURING A CRANK THROW, AND CRANK THROW

摘要

Provided is a method for forging a crank throw having high productivity and increasing fatigue strength of the crank throw. As a solving means, the method for forging a crank throw of the present invention includes: a process of measuring a position of a ghost portion in a rough forging collected form a steel ingot and a position of a ghost portion in the crank throw forged from the rough forging; a process of devising a relation a position of the rough forging before the forging or a position in the crank throw after the forging corresponding to the position of the steel ingot based on the measuring result, and estimating a position of the ghost portion in the crank throw after the forging from the position of the ghost portion in the rough forging before the forging based on the relation; and a process of determining a size of the steel ingot, a shape of the steel ingot, a position at which the rough forging is collected from the steel ingot and a forging method of the rough forging.