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Vacuum Heat Treatment Furnace

Vacuum Sintering Furnace

Vacuum Brazing Furnace

Flowmeter Vacuum Brazing

Mass flowmeter stainless steel vacuum brazing, nickel-based high vacuum brazing can be selected, high welding strength, small deformation, beautiful and bright appearance. The key points of the stainless steel vacuum brazing process include: brazing joint design, connection mode, positioning, gap, and placement of brazing filler metal. In addition, the surface of the workpiece needs to be treated before fiber welding. Details are as follows:

1. Design of Brazed Joint

When designing a brazed joint, many factors such as the strength of the joint, the positioning method of the assembly, the position of the brazing material, and the gap of the joint should be considered

2. Surface Treatment of Workpiece

Thorough removal of oxides, oil stains and dirt on the surface of the workpiece before brazing is a prerequisite for the mutual wetting and diffusion of the solder and the base metal to fill the weld.

3. Develop a Temperature Curve

The purpose of vacuum firing purification is to heat the vacuum furnace to a temperature of 80°C higher than the welding temperature for 1.5 hours to purify the atmosphere in the furnace, so that the evaporates of the base material and brazing filler metal in the furnace can be volatilized.

4. Remelting Temperature

The remelting temperature is very important for multi-stage vacuum brazing and re-welding of defective brazing seams to improve the yield. The remelting temperature is the melting point of the brazing seam after welding. The brazing filler metal melted during the brazing process of stainless steel interacts with the stainless steel, so that the composition of the brazing seam after welding is different from the composition of the brazing filler metal used.

5. Argon Partial Pressure Control Process

Vacuum brazing can be divided into high vacuum brazing and partial vacuum brazing according to different vacuum conditions. High vacuum brazing is suitable for brazing filler metals and base materials that contain less volatile elements and difficult to decompose oxides.

If the solder contains more volatile elements, in order to reduce the vapor pressure of these elements in the solder and base metal at the brazing temperature, and improve the quality of brazing.

6. Application Characteristics of Vacuum Brazing

Vacuum brazing technology can be rapidly developed and applied, mainly because it has a series of advantages compared with other welding methods.

1) During the whole brazing process, the parts to be brazed are under vacuum conditions (10-2Pa～10 Pa range), and there will be no oxidation, increase of joints, decarburization, pollution and deterioration, etc., and the cleanliness and strength of the welded joints Higher.

2) When brazing, the parts are heated uniformly and the thermal stress is small, and the deformation can be controlled to a minimum. It is especially suitable for brazing of precision products.

7. Deformation of Brazing Parts

1) Reason

The heating rate is large, the release stress is too fast or the thermal stress is too large, and the cooling too fast also causes the thermal stress to be too large. Insufficient tooling rigidity or insufficient clamping strength.

2) Elimination measures

Increase the stress relief annealing of brazed components before brazing; adopt staged heating, set up an isothermal platform, and quickly increase the temperature when it is close to the brazing heat preservation temperature;

The temperature is controlled in stages, and the temperature is slowly cooled below the solidus temperature of the solder. Improve tool rigidity and clamping accuracy.