Method of Making an Udersea Pipe, the Method Including Peening Assembly Welds Inside the Pipe

A method of making steel undersea pipes, the method comprising end-to-end assembly by welding of unit pipe elements with welds having steel or metal alloy weld beads, the steel or metal alloy weld beads of said welds being located on the outside of the pipe, wherein localized peening is performed inside the pipe to increase the compression of the steel or metal in said welds and over the adjacent peripheral inside surface of the pipe on either side of the weld so as to create a surface swath that is peened over a limited distance L in the axial longitudinal direction XX of said pipe, preferably over a distance L that is not less than the width of the weld, on the inside of the pipe, plus a width of 1 mm to 10 mm on either side thereof.