The invention discloses a vacuum
brazing method for a slender weld joint of a hole-shaft matched part. The method comprises the following steps of assembling the part, and spraying
brazing filler metal, specifically, spot-
welding a sheared
nickel sheet to a
conical surface part of a shaft-shaped part, and uniformly distributing the
nickel sheet at 3-5 parts along the circumferential direction of the
conical surface part; assembling, specifically, putting the shaft-shaped part in a hole-shaped part and assembling to the bottom, and enabling a clamping part to be in close fit with the inner wall of the hole-shaped part;
coating and injecting the
brazing filler metal, specifically, uniformly
coating and injecting the prepared paste brazing
filler metal on the edge of a gap formed by the shaft-shaped part and the hole-shaped part for a circle by using an
injector;
drying, specifically, cleaning the part, putting the part into a
drying oven at (80+ / -10) DEG C, and keeping the temperature for (40+ / -10) minutes; and conducting brazing in a furnace. According to the vacuum brazing method, the front end of the hole-shaft matched part is in close fit, and the
nickel sheets with the same thickness are uniformly distributed on the
conical surface along the circumference for
spot welding, so that the
welding clearance is doubly ensured, the conical surface is prevented from being stuck in the assembling process, and the brazing quality of the slender weld joint is better ensured; and the process is easy to operate, parts are easy to assemble, and part
assembly is not affected after the nickel sheets are preset on the conical surface.