A method for joining components made from ductile cast iron and made from ductile cast iron and steel, by arc welding with fusible electrodes under a gas blanket. The gas blanket comprises, in addition to argon, 1 to 25 vol. % carbon dioxide and/or 0.5 to 10 vol. % oxygen. The gas blanket can also comprise nitrogen monoxide. Said method permits high welding speeds and hence a high productivity. The joint quality can be further advantageously improved by means of a pre-heating of the components and a slow cooling or a post-treatment.