Understanding the parameters controlling friction stir welding of AISI 409M ferritic stainless steel

Empirical relationships were developed to predict the tensile strength and impact toughness of the friction stir welded AISI 409M ferritic stainless steel joints by incorporating process parameters, namely rotational speed, welding speed and tool shoulder diameter. The experiments were conducted based on a three factor, five level, central composite rotatable design matrix. Sensitivity analysis was carried out and compared with the relative impact of three process parameters on tensile strength and impact toughness to verify the measurement errors on the values of the uncertainty in estimated parameters. The results indicate that the welding speed has the greatest inuence on tensile strength and impact toughness, followed by rotational speed and tool shoulder diameter.