Welded metal bellows mechanical seal

Several semi-finished products are stacked and welded to the outer periphery, and finally the front and rear ring seats are welded to form the specified bellows. The main process is punching and forming of the wave plate-cleaning-inner seam welding-outer seam welding-welding front and rear seat rings-inspection-heat treatment-inspection.

One, blanking and forming

The blanking and forming of the wave plate can be completed at one time. The shape of the wave plate has a great influence on the performance of corrugated bone. At present, there are two kinds of grinding tools, one is metal grinding tool, and the other is polyurethane rubber blanking forming die. Because the end face of the former die is a forming curved surface, the precision requirement is high, the manufacturing is difficult, and the mold workload is large, it is difficult to correct the gap between concave and concave and concave, in the process of blanking and forming, the dislocation between the concave and convex dies is small, and the wave plate is generally not scratched.

Second, cleaning.

Wave plate cleaning is one of the important conditions to ensure the quality of welding, especially the inner and outer circumference of the weld treatment cleaning, wave plate need to wash, adjust cleaning, pickling, neutralization, water washing and drying, and then acetone soak, scrub.

Three, welding

The welding of bellows is a precision welding, so the operating room should have a complete air conditioning and air filtration system to ensure constant temperature, humidity and dust-free.

The welding of bellows does not use welding rods, but fusion welding is carried out in the air range (the working gas is Ar and the shielding gas is Ar N2) to avoid the formation of welding slag at the welding place and affect the inherent characteristics of the bellows material. In order not to generate surface stress during melting, the welding part should be welded into a semicircular spherical shape, and the welding roughs of the single-layer wave plate are usually 2.2-3 times the thickness of the wave plate, the double-layer wave plate is 4-5 times the thickness of the wave plate, the wave distance should be uniform, the shape of the welding shave should be symmetrical, and the welding process is mostly micro-beam plasma welding. This kind of welding machine is produced in batches in China, such as LH-16 micro-beam plasma welding machine.

Four, quality inspection

In the manufacturing process of corrugated pipes, the quality control is extremely strict. For example, when making corrugated pipes, metallographic microscopic examination of the grain size arrangement and microscopic examination of the plates should be carried out to understand the welding depth, the shape and symmetry of the welding shreds. All welds should be checked for air tightness. Helium mass spectrometer leak detector is usually used for leak detection. Vacuum leak is 1*10 mL/s. In addition, the elastic rate of the corrugated pipes should be accurately measured, the relaxation and hysteresis of the telescopic characteristic force, etc.

Five, the heat treatment of corrugated pipe

And the corrugated pipe of AM-350 material is a row, and its heat treatment must be carried out at 850 degrees in a vacuum furnace, and at a low temperature of -80 degrees (to cold F12) to achieve the purpose of increasing elasticity and stabilizing size.