S9074-AQ-GIB-010/248 Rev 1
f. For S-10H base materials, an increase or decrease in weld metal cooling rate over that originally used during qualification.
In order to accommodate this requirement, the welding procedure shall be qualified with two test plates, one with the maximum plate thickness, the minimum heat input, and the minimum preheat/interpass temperature and the other with the minimum thickness, the maximum heat input, and the maximum preheat/interpass temperature to be used during production welding. For the minimum heat input plate, the requirements of 4-4.1.13 shall also apply (i.e., at least 80 percent of beads shall be no more than 20 percent above the minimum heat input to be qualified and the average of all beads shall not exceed the minimum). Specific cooling rate values are not required to be determined. Plate thickness need not exceed 1.5 inches for this test; where production welding exceeds the normal 3-inch thickness limit of table 7-6 for a 1.5-inch test plate, either a plate exceeding 1.5 inches can be welded as above, or a 1.5-inch thick plate can be welded as above and a third plate of necessary thickness can be welded within the qualified parameters selected by the activity (e.g., heat input need not be the minimum). This testing may be reduced where solution annealed heat treatment is involved, if approved by NAVSEA.
For S-10H base materials welded to other than S-10H base materials with other than A-9A or A-9B weld metal, the welding procedure need not be qualified at the lowest cooling rate (minimum plate thickness, maximum heat input, and maximum preheat/interpass temperature) if cooled at a rate higher than the lowest rate at which an S-10H to S-10H weld was qualified. g. For stud welding, a change in the arc timing greater than ±10 percent. h. For drawn arc stud welding, a change in amperage greater than ±10 percent; for other stud welding, see 4- 4.4.h. i. For capacitor discharge stud welding, a change in charging voltage or machine capacitance above or below that used during qualification. j. For stud welding, an increase in maximum cable length or decrease in cable size from that originally qualified. 4-7.6 POSITION AND VERTICAL PROGRESSION. a. A change to a position other than one already qualified as specified in 4-2.8. b. For any base material where toughness testing is required by table 7-7, footnote 2, a change in weld progression from vertical-up to vertical-down, or vice versa, except root pass welds that are completely removed by back-gouging; also see 4-8.j for cladding and hardfacing, and for level II qualification, see 4-8.h.
4-7.7 SHIELDING GAS (TORCH, PURGE GAS, AND POWDER FEED GAS). a. A change from a mixture of gases to another mixture of gases or to a single gas. b. A change from a single gas to another gas or mixture of gases. c. For the plasma arc process, (1) A change in the orifice gas composition,
(2) A change greater than 5 percent in the flow rate of orifice gas, or (3) A change greater than 5 percent in flow rate of powder metal feed gas. d. A change in the nominal percentage of any non-inert gas in a gas mixture. e. When using a mixed inert gas, a change of ±25 percent or 5 cubic feet per hour (whichever is larger) in the flow rate of the minor constituents of the gas mixture.
4-25
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