During the past 20–30 years, there has been a worldwide trend towards the replacement of manual welding using flux covered electrodes with other processes allowing a higher deposition rate and having greater suitability for automation. 1 Although there are some particular features of the manual metal arc process2 that dictate that it will not be completely replaced in the foreseeable future, it is estimated that about 70% of weld metal will be deposited using more efficient processes. Use of continuous wires, in particular flux cored wires, is preferable owing to the versatility of these welding consumables, which allow the production of relatively small quantities of electrodes offering a wide variety of weld deposits having different chemical composition, exhibiting adequate mechanical properties for all positional welding. 3–5

In addition, it is well known that the employment of different protection gases as well as changes in the welding procedure parameters lead to variations in the deposit characteristics. 6–13 Generally the most frequently used gas for welding using rutile type flux cored wires is CO2, but it also possible to use Ar–CO2 mixtures. This type of protection results in improved appearance, less spatter, and greater arc stability. 6 Furthermore, in all arc welding