Influence of Baking Conditions of MMAW Electrodes on Weld Metal Mechanical Properties

Investigations have been carried out to study the influence of electrode baking temperatures and the duration of baking on the mechanical properties of the weldments with rutile and basic types of electrodes. It has been found that baking of rutile electrodes improves the weld-metal characteristics provided the baking is for short duration of 1 hour at 150°C. Higher temperature of baking leads to overall deterioration of mechanical properties. With basic type of electrode used for investigations, higher temperatures up to 350°C can be employed for shorter duration of one to two hours or 250°C for 2-3 hours baking, to achieve the optimum results i.e. good mechanical properties of the weld metal. Higher baking temperatures deteriorate the weld metal strength. The weld metal hydrogen content does not appreciably reduce beyond the baking temperature of 350°C basic coated electrodes.