Esab Atom Arc 8018-CM description: Atom Arc 8018-CM electrodes contain 1.25% Cr and 0.50% Mo as alloy addition. They are used for the welding of such steels as 0.5% Cr - 0.5% Mo, 1% Cr - 0.5% Mo, and 1.25% Cr - 0.5% Mo, which are used principally in power piping and boiler work for the fabrication of plates, pipes, tubes, castings, and forgings.