4. Temperature-Dependence of Metal Forming

This chapter first classifies metal forming into cold working (CW), warm working, and hot working (HW) and then discusses them with reference to their advantages and limitations to enable a manufacturing engineer to select the best type of metal forming. Cold working is explained both qualitatively and quantitatively by considering the increase in dislocation density as well as the changes in the microstructure and mechanical properties. The three stages of annealing (recovery, recrystallization, and grain growth) are described with the aid of formulae (including Avrami’s equation). Finally, hot working is discussed with reference to hot rolling to obtain refined recrystallized microstructure. This chapter contains 6 diagrams, 11 worked numerical examples, 7 MCQs, and 5 problems with their answers given at the end of the book.