Investigation of the joint properties of steel and aluminium plates welded by oxy gas welding method with hydrogen

In this study, utilization of hydrogen gas oxy gas welding methods had been for joining steel and aluminum sheets with of hydrogen gas had been investigated.80 mm long seams had been welded with horizontal butt weld method on 3 mm thick St 37 steel sheet and 3 mm thick 1100 aluminum sheets by employing oxy-hydrogen and oxy-acetylene welding methods. Identical welding speed and torch sizes, 115 mm/min and #2 (1 ? 2 mm) respectively, had been employed for both type of materials and welds had been conducted by the same welder.Tensile strength tests and micro hardness tests had been carried out on welded materials. Optical microscope had been employed for micro structure analysis of the specimens. Micro structures and hardness results of upper and lower yielding points, elasticity modulus, ultimate tensile strength had been compared for hydrogen gas welding and acetylene gas welding.Experimental studies revealed that oxy-acetylene welding resulted %8 ? 10 higher yield point for steel sheets compared to oxy-hyrogen welding and on the contrary oxy-hydrogen welding resulted %10 higher yielding point for aluminum sheets. Micro hardness measurements revealed that hardness values for all zones (as received metal, welded metal and heat affected zone) resulted higher values with oxy-acetylene welding compared to oxy-hydrogen welding.