METHOD OF WELDING INSIDE GROOVE MACHINED IN SOLID STEEL PART, AND UTILIZATION OF THE METHOD FOR REPAIRING CRACKED ROTOR

Process for welding a groove machined in a solid workpiece made of an alloyed steel wherein bottom passes (2) are effected by deposition using a non-alloyed steel as filler metal and then each wall (11, 13) of the groove is buttered with filler substances made of lightly-alloyed steel. A thermal treatment is carried out to eliminate the stresses in the zones (18, 19) of the part which are adjacent to the walls (11, 13) of the groove. The free space (20) between the two butterings (15, 17) is filled by filler products made of lightly-alloyed steel, the said wall-buttering operation (11, 13) being carried out by disposing in the groove a plate made of carbon steel at a certain distance from the said wall (13, 11), by filling the space between the plate and the wall (11, 13) by layers (14, 14') made of lightly-alloyed steel with a carbon content between 0.08% and 0.12% and by removing the steel plate and optionally a portion of the filling in order to leave only one layer (15, 17) over the wall (13, 11). Use for eliminating a defect in a part while strongly reducing the risk of cracking.