AWS C3.4M/C3.4:2016 pdf free download

AWS C3.4M/C3.4:2016 pdf free download.Specification for Torch Brazing.
The plating shall extend 2.5 mm 10.10 inj minimum beyond the brazed joint area indicated by the brazing symbol on the engineering drawing unless the part configuration does not permit this allowance. In addition, nickel plate may be specified by the Organization Having Quality Responsibility to cover any area or the entire surface of details or assemblies at its discretion. When the drawing or purchase documents do not specify localized plating, the components may be completely plated.
PRE€’A UTION: When using nickel plating, phosphorus or sulfur—potential ingredients in the ijickel plating—may interact with steel to form iron phosphides or sulfides when heated to over 815°C 11500 °FJ. Temperature monitoring shall be used, whenever possible, when heating to ensure the nickel plating will hot interact wit!, the base metals and form deleterjous phases.
5.4.3 joint Clearance. Joint clearance between laying surfaces to be torch brazed shall be controlled by the assembly procedures so that proper joint clearance at the brazing temperature is provided. When one of the faying surfaces is cross- hatched or straight-line knurled in the direction of brazing filler metal flow into the joint, a line-to-line fit is permitted. The depth of such knurling shall not exceed 0.13 mm [0.005 in] below the original surface. Suggested joint clearances for typical materials may he found in the AWS Bracing Handbook.
5.4.4 Tack Welding. When tack welding is required to maintain proper positioning of components, the tack weld size, location, and welding filler metal shall be specified on the engineering drawing or in writing by the Organization Having Quality Rcsponsibility. Tack welds shall be applied with adequate inert gas shielding per the approved welding procedure to assure that oxide contamination of the braze joint surfaces does not occur.
5.4.5 Accessibility. Joints to be torch brazed in place shall be accessible for proper preparation, assembly, heating, flux and brazing filler metal application, cooling, flux removal, and for the proper performance of all required inspections. Inaccessibility bears no justification for the waiver of any requirement of the engineering drawing or of this specification.
5.4.6 Application of Brazing Filler Metal. Brazing filler metal shall be introduced as defined in the BPS. Filler metal placed outside of the joint shall be applied as to be drawn onto the joint surfaces by capillary action during brazing.
Brazing filler metal quantity and placement shall be sufficient to yield satisfactory joints without buildup on adjacent surfaces that may interfere with part function. After the brazing filler metal application, assemblies shall be protected from contamination by su i table means.AWS C3.4M/C3.4:2016 pdf free download.