UTILISATION OF THE PENETRATION FOR FILLET WELDS

The penetration obtained with automatic submerged arc welding is very good and can be determined as a function of the current, electrode diameter and welding speed. The quality of the base material, its dimensions and the filler metal are of secondary importance. The weld quality is fully satisfactory for a penetration corresponding to a value of up to 100 percent of the throat thickness. Submerged arc welding with a large penetration is fully comparable with manual welding as regards the static and dynamic strength and in certain respects even superior. The penetration in fillet weld can be tested ultrasonically by mean of a halv-echo method, which has already been reported, or a new and in several respects better method, the zero-echo method. A proposal for rules for the utilisation of the penetration has been prepared on the basis of the experience and results obtained. These permit a reduction in the nominal throat thickness of 30 to 45 percent depending on the scope of the inspection. (Author)