Lihua Technology(HK) Industrial Co., Ltd.

Focus on Induction heating for 19 years

Large manufacturer of Induction heating automation equipment

+86 135 3907 6945
Lihua Technology(HK) Industrial Co., Ltd.

Brazing Seam Defects and Prevention

Some common shortcomings of brazing seam and prevention plan:
1. Gas trapping, welding bead
Caused by:
(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.
Prevention plan:
(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
Caused by:
(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
Prevention plan:
(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 weldment


3. Gap is not full
Caused by:
(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
Prevention plan:
(1) Use suitable flux
(2) Ensure sufficient amount of solder
(3) Select and maintain precise gaps
(4) Eliminate burrs carefully
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