PROPERTIES OF ELECTRON-BEAM-WELDED AND LASER-WELDED AUSTENITIC FE-28MN-5AL-1C ALLOY

Austenitic Fe-28Mn-5Al-1C alloy was welded by electron-beam and CW CO2 laser techniques. Tensile tests, impact tests, potentiodynamic and cy clic polarization measurements were used to evaluate the mechanical pr operties and corrosion behaviour of the weld materials. Metallographic examination showed that the microstructure of the electron-beam-welde d and laser-welded metals consisted mainly of the columnar and equiaxe d austenitic structures. Grain growth in the heat-affected zone (HAZ) was minimal for welding with these two techniques. The tensile and imp act tests indicated that the weld materials exhibited lower tensile st rength, percentage elongation, percentage reduction in area and impact energy than those of the base alloy. The polarization measurements re vealed that the anodic polarization behaviour of the HAZs of the elect ron-beam-welded and laser-welded materials was identical to that of th e base alloy when exposed in 1 M Na2SO4 solution. However, the electro n-beam-welded and laser-welded metals exhibited a higher current densi ty in the passive region than that of the base alloy when exposed to 1 N H2SO4 acid solution.