AWS C3.2M/C3.2:2019 pdf free download

AWS C3.2M/C3.2:2019 pdf free download.Standard Method for Evaluating the Strength of Brazed Joints.
5.2.5 The faying surfaces shall be prepared for brazing by a procedure suitable to the material and similar to that to be used for the production parts. This may include, but is not limited to, grit blasting, etching, abrading, plating, or solvent cleaning of the surfaces to be joined (see Figure 4.1, Surface S). Nonmetallic grit such as glass beads, sand, or alumina should not be used because it can negatively affect wettability.
5.2.6 When flux is used, the flux classification from AWS A5.31 M/A5.31, or other descriptive information, including the lot or batch number, shall be included on the test data sheets. When a protective atmosphere is used, it should be specified on the data sheet along with the dew point or vacuum pressure (see Figure 4.4).
5.2.7 The configuration and recommended tolerances for the preparation of the double-lap shear test specimen prior to brazing are shown in Figure 5.1. The specimen may be assembled by tack welding using a suitable welding method, or it may be held by a suitable fixture during brazing. The joint clearance should be the optimum recommended for the brazing filler metal being tested unless the objective of the test is to determine the effect of clearance or other variations on joint strength. For further information, the AWS Brazing Handbook provides clearance recommendations for the various classes of brazing filler metals and brazing processes. To aid the assembly of the specimen blank, a fixture similar to that shown in Figure 4.3 can be used.
The joint clearance can be established and maintained by inserting spacers between the specimen blanks along the edges of the joint area. The spacers should be of the same composition as the base material or a metal that has minimum reaction with the base material and brazing filler metal. The introduction of a third material as the spacer may result in an interaction between the brazing filler metal and spacer material during brazing, which could affect the joint properties.
5.2.8 If the brazing filler metal is used in the form of powder, paste, or wire, it should be applied as shown in Figure
5.1. The amount of brazing filler metal should be the minimum that will completely fill the joint. Experimentation may be required to determine the proper amount for the joint area. Brazing filler metal strip may be placed in the joint. The quantity should be controlled to fill the joint completely with minimum excess, thus producing a minimum fillet size. The brazing filler metal classification, as shown in AWS A5.8M/A5.8, or the chemical composition, should be listed on the data sheet (see Figure 4.4).
5.3 Brazing Procedure. Specimens shall be brazed using a controlled procedure that simulates the actual process conditions as closely as possible. AWS C3.2M/C3.2:2019 pdf free download.