Dip brazing method with a preset temperature gradient

Abstract

The invention discloses a dip brazing method with a preset temperature gradient. The dip brazing method comprises the following steps that firstly, a circular separating plate is horizontally arranged in a brazing furnace, and the inside of the brazing furnace is divided into at least two relatively independent spaces by the circular separating plate; the upper part and the lower part of the brazing furnace are respectively heated by heating bodies in different power, fusion brazing material in the brazing furnace forms a temperature gradient that the temperature is gradually raised from bottom to top, a workpiece is dipped into the fusion brazing material to be brazed, and the temperature each part of the workpiece is the same as the temperature of the fusion brazing material in contact with the workpiece; and the workpiece is slowly moved out, the brazing material at the bottom of the brazed workpiece is firstly solidified, then the brazing material is gradually solidified in an upward sequencing way, and gas in brazing seams is exhausted out in the solidifying process, so as to complete the brazing process. The invention also discloses a special brazing furnace. The dip brazing method and the special brazing furnace have the advantages that the problems of multiple gas holes, low brazing efficiency, instable quality of the product, large energy consumption and the like in the brazed workpiece during dip brazing are well solved; and the structure of the brazing furnace is simple, the operation is convenient, different temperature gradients can be set according to different process requirements, and the brazing requirements of different brazed workpieces are met.

Description

technical field [0001] The invention relates to dip brazing technology, in particular to a dip brazing method with a preset temperature gradient, and also relates to a dedicated brazing furnace for the dip brazing method. Background technique [0002] Dip brazing is a technology that immerses part or the whole of the weldment in molten solder or mixed salt tank, and heats the workpiece to the brazing temperature by means of heat conduction of the liquid medium to achieve brazing. Dip brazing has fast heating speed, uniform heating, high production efficiency, small deformation of welded parts, no obvious grain growth and decarburization, and can protect welded parts from oxidation, and accurate temperature control during brazing (±5 o C), easy to realize mechanization, and is widely used in industry. However, in the traditional immersion brazing process, the brazing furnace needs to be continuously heated, and the temperature field in the furnace is high in the middle and l...

AI Technical Summary

Problems solved by technology

However, in the traditional immersion brazing process, the brazing furnace needs to be continuously heated, and the temperature field in the furnace is high in the middle and low on the surface. The removal path of gas impurities is closed, the gas is not easy to discharge, and defects such as pores are formed, causing defects such as poor density of the brazing seam and low brazing rate, and unstable product quality

For weldments with complex shapes, gas discharge is more difficult, and product quality cannot be guaranteed

In order to improve the brazing quality, the commonly used method is to extend the immersion time, which increases energy consumption and environmental pollution.

Images