Abstract: A method of welding in a groove (1) machined in a solid alloyed steel part, characterized in that bottom passes (2) are performed and then each wall (11, 13) of the groove (1) is faced with low alloy steel filler material, heat treatment is performed so as to eliminate the stresses in the zones (18, 19) of the part adjacent to the walls (11, 13) of the groove, and the empty space (20) between the two facing layers (15, 17) is filled with low alloy steel filler materials, said operation of facing the wall (11, 13) being performed by placing a carbon steel plate (4, 4', 2, 22') in the groove (1) at a certain distance from said wall (13, 11), by filling the space (12, 16) between the plate (4, 4', 22, 22') and the wall (11, 13) with layers (14, 14') of low alloy steel having a carbon content lying in the range 0.08% and 0.12%, and by getting rid of the steel plate (4, 4', 22, 22') and optionally a portion of the fill so as to leave only a layer (15, 17) on the wall (13, 11).