EFFECT OF WELD TYPE AND POST WELD HEAT TREATMENT ON THE CORROSION RESISTANCE OF AISI 321 STAINLESS STEEL

This work has investigated the effect of lap joint and butt joint electric arc welding together with their post weld heat treatments on the corrosion characteristic (resistance) of a stabilized AISI321 stainless steel in a tar sand digester. Water quenching and furnace cooling were the two heat treatment procedures carried out on the welded samples. The corrosion experiment was by the non-electrochemical technique and the analysis of the result was by corrosion rates determination in mils per year (mpy). The tar sand used for investigation was analyzed using energy dispersive x-ray analyzer (EDXA). The result of this work include a comparative analysis of the composite results of the various corrosion rates produced for the welding joint type and the heat treatment procedure. The butt joint welded water-quenched AISI 321 stainless steel came out to be most resistant than the other combinations. The furnace cooled heat-treated lap joint welded stainless steel exhibited the least resistance in the tar sand environment