Thermal model for friction stir welding of mild steel

• Published in: Multidiscipline modeling in materials and structures 2013-01, Vol.9 (1), p.49-61
• Main Authors: Selvaraj, M, Murali, Vela, Koteswara Rao, S.R
• Format: Article
• Language: English
• Subjects: Carbon steels; Computer programs; Friction stir welding; Heat generation; Heat sources; Low carbon steels; Mathematical models; Rotational; Welding
• ISSN: 1573-6105; 1573-6113
• DOI: 10.1108/15736101311329151

Purpose - The purpose of this paper is to propose a three-dimensional thermal model for friction stir welding of AISI 1018 mild steel to predict the thermal cycle, temperature distribution, the effect of welding parameters on power required, heat generation and peak temperature during the friction stir welding process.Design methodology approach - The mathematical expressions for heat generation during the friction stir welding process were derived. The simulations for various welding and rotational speeds were carried out on ANSYS software employing temperature and radius dependent moving heat source and applying the boundary conditions.Findings - The predicted thermal cycle, torque required and temperatures were found to be in good agreement with the experimental results. The heat generation and peak temperatures were found to be directly proportional to rotational speed and inversely proportional to welding speed. The rate of increase in heat generation and peak temperature were found to be higher at lower rotational speeds and lower at higher rotational speeds. The heat generation during friction stir welding was found to be 71.4 per cent at shoulder, 23.1 per cent at pin side and 5.5 per cent at bottom of the pin.Originality value - A new temperature dependent slip factor has been used to determine the contribution of slipping and sticking on total heat generation. A temperature and radius dependent moving heat source has been employed.