Welded joints--Testing

A series of experiments were performed on aluminum-steel explosively welded joints. The pub of this research was to better understand the synergism, if any, between thermal heat treatments and exposure to a seawater environment on the tensile-shear strength of the explosively welded joint. The effect of three different heat treatments on the tensile-shear strength of the bond was examined. The combined effect of two heat treatments and immersion in flowing aerated, natural seawater has been studied for two different corrosion times. For comparison purposes, some samples were also immersed in stagnant, aerated 3.5% weight NaCl solution. Open circuit potential measurements and microhardness profiles were also made. It was found that a heat treatment that would anneal the aluminum without causing the formation of an intermetallic layer at the aluminum steel explosively welded interface, was the best compromise between reduced mechanical properties and improved corrosion resistance.