S9074-AR-GIB-010/278 7. WORKMANSHIP REQUIREMENTS
7.1 General. This section contains the minimum requirements for workmanship practices and methods to ensure sound welded joints.
7.2 Cleaning prior to and during welding. The joint members to be welded, including the base metal surfaces, shall be cleaned to remove foreign material for a minimum of 1 inch from the weld edge. Mill scale or metallic oxides shall be removed from surfaces where weld metal will be deposited. Slag shall be removed from all weld metal surfaces prior depositing subsequent passes or layers and upon completion of the weld. For S-1OH materials, wire brushing shall be accomplished using stainless steel brushes which have not been used on alloys other than stainless steel. 7.2.1 Seal welding in areas have threaded connections. Threads in the seal weld and inspection areas of threaded connections shall be removed prior to welding and subsequent inspection. 7.2.2 Titanium preweld preparation. As a minimum, all contaminants shall be removed from the weld joint surface (i.e..... surfaces to be welded over) and the adjacent 1-inch of material prior to welding. Weld joint surfaces shall also be free of discoloration. Preparation of surfaces shall not deposit iron or other deleterious contaminants that are not subsequently removed from base metal surfaces. Unless otherwise approved by NAVSEA. the following shall be performed, as a minimum, prior to welding. Forged and cast surfaces and surfaces heat treated in air which will be welded over shall require a minimum of 1/32 inch metal removal. Weld joint should be prepared by machining with carbide or ceramic tools. If high-speed steel tooling is used, weld joint surfaces shall be dressed with carbide burrs to remove any embedded steel particles. Weld joint surfaces prepared by shearing, sawing, etc. shall also be dressed with a carbide burr to remove all surface markings from the cutting operation (see 11.3.1 for cleaning of thermal cut surfaces). The final surfaces shall be brushed with a stainless steel wire brush, and then wiped along with 1 inch of adjacent material with a solvent. 7.2.3 Titanium interpass cleaning. Where required, discoloration shall be removed by burring or filing type operations. Except for S-53 materials, straw color may be removed by stainless steel wire brushing. Should discoloration of a weld bead occur, the cause shall be determined and corrected prior to further welding. Where cleaning and defect removal type operations on weld beads in titanium materials are performed, requirements of 7.2.2 shall be met. 7.3 Peening of welds. Welds may be peened to help control distortion, to relieve stress, or to improve weld quality. When peening is performed on weld layers subject to nondestructive evaluation, all visual evidence of peening or smeared metal shall be removed. Peening of the first or last layer of pipe welds shall not be performed. Peening shall be performed with a round or blunt- nosed tool of circular or oblong cross-section. Welds shall not be overpeened, causing flaking and laps or reducing the cross-section of the adjacent base metal. Surface slag, slag inclusions, cracks, porosity, and other weld defects shall be removed prior to peening. Welds in S-51 and 5-52 materials shall only be peened using
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