DIYALA JOURNAL OF ENGINEERING SCIENCES

Abstract

This research deals with influence of the MIG/MAG spot welding process on the mechanical properties of the spot weldment of low alloy steel (ASTM A242) and the determinations of optimum conditions for the spot welding variables , welding current and time for thickness (2.5,5mm) with shielding gas Ar and Co2 . Results show that the maximum shear force for the spot weldment would increase with increasing of the welding current and time to specific amount, after words the shear force would drop at the higher currents and longer time. For (2.5mm) thickness the maximum shear force was (20.6KN) at welding current (280AMP.) and welding time (5Sec.) for the Co2 shielding gas while for the same thickness with Ar shielding gas the maximum shear force was(22.2KN) at welding current (265AMP.) and welding time (5Sec.). with (5mm) thickness the maximum shear force reached (35.2KN) at welding current (330AMP.) and time (5Sec.) when Co2 shielding was used while for the same thickness with Ar shielding gas the maximum shear force was (37.1KN) at welding current (315AMP.) and welding time (5Sec.)