An Analysis of Efficiency Parameter and its Modifications Utilized for Development of Processing Maps

The efficiency parameter, which is frequently utilized in the literature, can be expressed as η=(2m/m+1), where m is the strain rate sensitivity. The efficiency parameter is determined from a set of m values based on the strain rate and the temperature displayed in a three-dimensional map known as the power dissipation map. This method works if the test results for σ vs. 𝜀̇ at constant strain and temperature have a power-law distribution. Otherwise, it is incorrect to assess dissipation efficiency using the of the 𝑙𝑛𝜎 − 𝑙𝑛𝜀̇ graph. The present study proposes additional adjustments to the existing ones suggested in the literature for the prior technique by offering a scheme for evaluating η. Power dissipation maps for different techniques are developed at strains of 0.2 and 0.7 using X80 steel as a model material. In spite of the fact that the approaches rely on different assumptions and that there are differences in the temperature and strain rate at which the dissipation efficiency peak appears, there are some similarities in the power dissipation maps of all approaches when they are compared at different strains. In conclusion, although the conventional approach is erroneous, it is the most feasible and straightforward one.