Some common shortcomings of brazing seam and prevention plan:1. Gas trapping, welding bead
(1) In the gap between the parallel planes, it is caused by the uneven caulking rate of the liquid flux and the solder, and the irregularity of the forefront of the caulking, resulting in "small envelopment".
(2) The rapid fluidity of the solder along the lap joints of the welded steel bars in the external field causes "enclosure".
(3) Uneven heating.
(1) Choose a suitable gap to prevent it from being too large or too small; for connectors with high tightness requirements such as tee joints, you can choose different gaps, and pay attention to the brazing temperature and time to facilitate exhaust pipes and slag removal.
(2) Pay attention to the matching of the melting point of the solder and the solder.
(3) The amount of flux should be moderate.2. Vent hole
(1) The brazing temperature is too high or the heat insulation time is too long
(2) The flux reflects the vapor that is transformed into and the vapor melted in the filler metal
(3) Precipitating vapor from brazing metal materials
(1) Reduce brazing temperature and reduce heat insulation time
(2) Degassing of borer material, select suitable borer material and flux
(3) Weldments with specified tightness should be made of materials without vapor and impurities
(4) Eliminate the air oxide film on the surface of the weldment3. Gap is not full
(1) The unreasonable use of the flux leads to incomplete removal of the film, poor specificity of the flux, and unsuitable melting point
(2) Insufficient amount of solder
(3) The gap on the street is too large or too small
(4) The burrs are rolled up to prevent the filler from filling the joints
(1) Use suitable flux
(2) Ensure sufficient amount of solder
(3) Select and maintain precise gaps
(4) Eliminate burrs carefully