Surface Roughness Optimization in Hard Turning of AISI D2 Steel Using RSM and Machine Learning. International Research Journal of Innovation in Science and Technology, [S. l.], v. 1, n. 2, p. 8–15, 2026. Disponível em: https://irjist.org/index.php/irjist/article/view/10. Acesso em: 9 may. 2026.