AWS D8.1M pdf free download

AWS D8.1M pdf free download.Automotive Weld Quality- Resistance Spot Welding of Steel.
3. Terms and Definitions
The terms listed in AWS A3.OM/A3.O, Standard Welding Terms and Definitions, Including Terms for Adhesive Bonding, Brazing, Soldering, Thermal Cutting, and Thermal Spraying, shall apply to this document, except for those listed below.
aspect ratio. The ratio of the maximum dimension to the minimum dimension of the fused area.
button. The part of a spot weld which tears out during destructive testing of welded steel. It may include all or part of the nugget, the heat-affected zone (HAZ). and base metal. A hole is left in the mating sheet(s).
button pull. A fracture mode of a spot weld where separation occurs through the heat-affected zone ([IAZ) of the weld, resulting in a button (see example in Figure 10).
button size. The average of the maximum and minimum dimensions of the button.
edge weld. A spot weld area, as defined by the impression left by the electrodes, which is not fully contained within all original edges of the sheet metal.
fracture mode. The appearance of the weld after destructive testing as categorized in Figures 10 through 17.
fused area. The area of the nugget at the faying surface (interface between the metals being joined). The fused area may result in button pull. partial thickness fracture, interfacial fracture, or combinations thereof.
fusion zone. The volume of fused base metal resulting from the welding process. The fusion zone is visible when a weld is cross-sectioned and suitably etched.
governing metal thickness (GMT). The metal gage in a stack-up that determines the minimum acceptable weld size. The GMT for a two-sheet stack-up is the metal thickness of the thinner of the two sheets. Generally, the GMT for a three-sheet stack-up is the metal thickness of the second thickest sheet.
heat-affected zone (H AZ). The portion of base metal adjacent to the nugget whose mechanical properties or micro- structure have been altered by the heat input from welding.
indentation. Indentation is the ratio of the amount of weld depression to the prewelded sheet thickness, expressed as a ratio. interfacial fracture. A fracture mode of a spot weld where all of the weld nugget separates through the plane of the
weld at the faying surface. It’ less than approximately 20% of the mating sheet thickness is removed, the fracture is interfacial (see example in Figure 16).
partial thickness fracture. A fracture mode of a spot weld where a part of the weld nugget shows removal of parent metal by the weld from the mating sheet. This mode may or may not include some button pull. The portion removed must be at least approximately 20% of the mating sheet thickness, otherwise the fracture is interfacial. A cavity is left in the mating sheet (see example in Figure 12).
penetration. Penetration is the ratio of the nugget’s maximum depth of fusion to the prewelded sheet thickness, expressed as a percentage.
stack-up. The number of sheets and materials being joined by the spot weld.
weld size. The average of the maximum and minimum dimensions of the fused area in destructive inspection or the nugget width in metallographic inspection.AWS D8.1M  pdf download.