S9074-AQ-GIB-010/248 Rev 1
6-3.9 PROCEDURE QUALIFICATION TEST REQUIREMENTS. The brazing procedure shall be qualified where required by 6-3.1.b as follows: 6-3.9.1 Qualification Test Assemblies. Base materials and brazing alloys shall be as specified in tables 7-13 and 7-14. The size of each test assembly shall be sufficient to permit removal of the required test specimens. The method used in brazing the qualification test assemblies shall be in accordance with proposed brazing procedure. No repair of test joints is permitted. Qualification shall be obtained for the position to be used in production, except qualification in either the flat-flow, vertical-up flow or horizontal-flow position shall also qualify the vertical-down flow position (see figure 7-23). Material thickness limits are shown in table 7-15. Butt or scarf joints shall qualify for lap joints and vice versa. The type and number of tests shall be as specified in table 7-15. 6-3.9.2 Qualification Assembly Destructive Test Evaluation. 6-3.9.2.1 Tension Test. Reduced specimens conforming to figure 7-19 shall be used for tension tests. The stress shall be computed by dividing the ultimate load by the nominal total cross-sectional area of the thinnest member comprising the joint. The tension specimen shall have, as a minimum, a tensile strength that is not less than: a. The specified tensile strength of the base material in the annealed condition. b. The specified tensile strength of the weaker of the two members, in the annealed condition, if materials of different specified minimum tensile strengths are used. c. If the specimen breaks in the base metal outside of the braze, the test shall be accepted as meeting the requirements, provided the strength is not more than 5 percent below the specified tensile strength of the base material in the annealed condition. 6-3.9.2.2 Peel Test. The peel test specimen shall conform to figure 7-20. The peel specimen shall show evidence of brazing alloy along each edge. Specimens shall be separated or peeled either by clamping “section A” and striking the fulcrum point with a suitable tool or by clamping “section A” and “section B” in a machine suitable for separating the sections under tension. The separated faying surfaces of joints shall meet the following criteria: a. The total area of defects, unbrazed areas, flux inclusions, and so forth, shall not exceed 30 percent of the total area of any faying surface. b. The sum of the lengths of the defects measured on any one line in the direction of the lap shall not exceed 25 percent of the lap. 6-3.9.3 Qualification Assembly Nondestructive Test Inspection. Prior to destructive testing, brazements shall be visually (VT) inspected to the following acceptance standards: a. Excess braze metal. Braze filler metal in excess of that required by (c) is acceptable, provided the excess alloy does not interfere with the function of the completed assembly. b. Residual flux. Visual evidence of residual flux is not permitted on the surface of a completed joint. c. Evidence of brazing alloy on completed joints. Brazed joints shall be considered acceptable when the total length of exposed brazing alloy along the length or perimeter of the joint is equal to or greater than three-fourths of the joint length. d. Unmelted filler metal. There shall be no unmelted filler metal. e. Cracks. There shall be no cracks. 6-3.10 CHANGES REQUIRING REQUALIFICATION OF BRAZING PROCEDURES. A revised brazing procedure shall be prepared and the procedure requalified when any of the changes specified in 6-3.10.1 through 6- 3.10.8 are made (except where qualification is not required as specified in 6-3.1). Changes other than those specified in 6-3.10.1 through 6-3.10.8 may be made without requalifying the procedure but must be documented in the revised procedure.
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