| 摘要 |
PURPOSE:To prevent the attack of base metals by brazing filler metals by performing the temp. elevation of materials to be treated through force circulation of an atmosphere and radiation heating and holding the materials at the treating temp.only through the radiation heating during brazing in Al brazing work using a protecting atmosphere. CONSTITUTION:The work W to be brazed is put in a drying chamber 2 and preheated and dried to about 200 deg.C. Next, the work W is loaded into a vestibule 4, and after the inside of the vestibule 4 is evacuated and degassed to a vacuum, gaseous nitrogen as an inert gas is introduced to decompress and purge the furnace inside, whereby the work W is cleaned. Thereafter, the work W is loaded into a brazing furnace 6, where the work W is quickly heated up to around the melting temp. of a brazing filler metal through the radiation heating by a heater 9 and the convection heating by a circulation fan revolving at high speeds. Next, the fan 11 is stopped, and the work is heated up to the brazing temp. only through the radiation heating by the heater 9, whereby it is brazed. There is no material degration of the brazing filler matal owing to the impurities in the circulating gaseous atmosphere, and the corrosion of the brazed material is prevented. |
