AWS D8.7M pdf free download

AWS D8.7M pdf free download.Automotive Weld Quality- Resistance Spot Welding.
4.1 Weld Process Control. Production welded parts that are joined by the resistance spot welding process have continually changing weld quality characteristics. Toler- ances must be established for the required quality to be consistent with the manufacturing process capabilities. The welding process must be controlled to maintain (or exceed) minimum weld quality level that meets the prod- uct requirements. Information and guidance pertaining to supplier requirements for process and product control are contained in the Quality System Requirements, QS-9000 Third Edition or the latest edition of ISO/TS 16949 Qual- ity systems- Automotive suppliers- Particular require- ments for the application of ISO 9001:2000, published by the Automotive Industry Action Group (AIAG) (see Annex B).
4.2 Satisfactory Weld. A satisfactory weld has a nugget width or button (see 5.1.1) greater than or equal to the minimum weld size and satisfies the other criteria in Sec- tion 5, Weld Quality Evaluation Criteria. Tool design and set-up are based on a weld size larger than the mini- mum. As production welding continues, the weld size can vary down to the minimum value. When this deterio- ration becomes apparent, adjustment of the equipment or electrode maintenance, or both, is required to re-establish the weld dimensions near the set-up weld size.
4.5 Weld Through Sealers and Adhesives. Sealers and adhesives are acceptable provided welds meet the requirements of this recommended practice.4.6 Part Fit-Up. Mating parts should make contact at the faying surface with adequate fixturing and clamping, avoiding increases in electrode force. To assure good joint fit-up, all parts should be properly positioned and accurately located.4.7 Weld Identification. Automotive manufacturers and suppliers use special symbols to identify a weld or group of welds. These symbols may be unique to each automo- tive manufacturer. The symbols are used to identify welds that require additional or special attention. A listing of these symbols and their meanings are con- tained in Section II of the Quality System Requirements, QS-9000 Third Edition published by the Automotive Industry Action Group (AIAG).7.2 Chisel Test. A chisel test consists of forcing a tapered chisel into the lap on each side of the weld being tested until the weld or the joint separates resulting in a pulled button or intrfacial failure. The edges of the chisel must not touch the weld being tested (see Figure 13). This type of test should be used when a peel test is not practical. The weld acceptance is based on the same criteria as for the peel test.7.4 Tensile-Shear Test. A tensile-shear test is a quasistatic test by pulling lapjoined specimens (Figure 15) on a tensile testing machine. To minimize the influence of pulling speed, the test should be conducted at a speed of at most 15 mm/min. Shimming at the grips is needed to avoid excessive bending of the specimen if the thicker sheet is more than 1 .5 mm. The metrics that can be mon- itored include the peak value of load (peak load), dis- placement up to the peak load, energy defined by the area under the load-displacement curve up to the peak load (Figure 16), and failure mode (Figure 17).AWS D8.7M pdf download.