How to determine the cooling speed of vacuum brazing furnace parts

How to determine the cooling speed of vacuum brazing furnace parts

Weldment cooling is done at the end of the soldering heat preservation, but the rate of cooling is have effect on the quality of the joint. Cooling speed too slow, may cause the grain growth of parent metal, solder with parent metal interaction time growth, leading to excess of parent metal to dissolve in the solder, produce corrosion defects; To speed up the cooling speed, which is beneficial to refine brazing seam organization, thus improve the joint strength; But cooling speed too fast, may make the welding crack due to excessive internal stress formed, may also be due to the brazing seam rapid solidification doesn't make the gas evolution and formation porosity. Therefore specific to determine the cooling speed, must be combined with weldment size, by synthetically considering all kinds of factors such as parent material types and solder.