Preform necessity and preform design at hot closed-die forging – a general design approach

The parts obtained by forging are better than those manufactured by any other metalworking process in many aspects. This determines their widespread use where human safety and reliability are critically important. Industries such as aerospace, defence, automotive and agriculture, construction, mining are some of the largest customers using forged parts. The design of hot closed-die processes very often requires engineers to deal with two important challenges - the necessity of preform (intermediate) steps and the shape of these intermediate steps. A general design approach for determination of necessity of preforms and their shape at hot closed-die forging is presented in this article.