Khammas Hussein A. Predication of A Mathematical Model for A Hardness in Steel-52100. J. eng. sustain. dev. [Internet]. 2014 Sep. 1 [cited 2025 Apr. 22];18(5):134-48. Available from: https://jeasd.uomustansiriyah.edu.iq/index.php/jeasd/article/view/954