1. Surface pretreatment of stainless steel pipe cutting machine:
The surface oxide scale and other impurities are removed by sandblasting, and the outer surface of the elbow reaches the Sa2 level specified by the standard.
2. Non-destructive testing:
1) 100% UT or RT inspection shall be carried out for each elbow welding seam, and RT inspection shall be carried out for the repaired welding seam. Comply with the requirements of the standard.
2) After the groove is prepared, magnetic particle or penetrant testing is performed on the entire nozzle and the 100mm length of the weld at the beginning of the nozzle, and the grade I is qualified.
3) Magnetic particle or penetration testing shall be performed on the 90° arc surfaces on both sides of the outer arc of each elbow pipe, and the depth of the defect shall not be greater than 5% of the wall thickness.
4) For the pipe body within the range of ±45° from the neutral plane where the outer arc side of each elbow is basically constant with the wall thickness, UT is used to inspect the transverse crack defect.
5) According to SY/T6423.5 or SY/T6423.6, perform layered curve detection on the elbow, which meets the requirements of the standard.
6) Residual magnetism: check and demagnetize in accordance with relevant regulations, no more than 15Gs.
3. Appearance inspection of stainless steel pipe cutting machine:
1) There are no cracks, overheating, overburning; no hard spots on the surface;
2) Whether the inner and outer surfaces of the stainless steel pipe cutting machine are smooth, with sharp gaps, delaminations, nicks, scars, cracks, folds, tears, cracks, cracks and other defects.
3) It is not allowed to have a pit with a depth of more than 3.15mm on the pipe body of the stainless steel pipe cutting machine or a pit with a depth of more than 1.5mm on the welding seam, and it is not allowed to repair the dent by hammering.
Noise and resonance: Noise affects the comfort of users using pipe bending equipment, and is an important indicator to measure the quality of pipe cutting machines. The noise of domestic high-power pipe cutting machines is generally above 80dB, especially in places with low temperature, not only the noise is large, but also the phenomenon of resonance. The noise of foreign high-power pipe cutting machines is generally below 76dB. The frame of the stainless steel pipe cutting machine is a welded box structure, similar to a speaker, which amplifies the noise. At the same time, in places with low temperature, the motion resistance increases due to the increase of the viscosity of lubricating grease and the shrinkage of the sealing ring, which further aggravates the generation of noise. During the welding process of the frame, it is necessary to ensure the quality of the welded parts, reduce the welding deformation, and add appropriate reinforcing ribs, so that the sound box effect is difficult to form. At the same time, the use of low-temperature-resistant lubricating grease and sealing ring can reduce noise.
Problems in the development and design of stainless steel pipe cutting machine: The pipe cutting machine has problems such as the deformation rate of the elbow section does not meet the national standard, the angle compensation of the elbow is difficult to control, the service life of the chain is not enough, and the control circuit is easily damaged. These belong to the design problems, and the finite element technology analysis is adopted for the weak links, and the ideal results can be obtained by optimizing the design of the parameters. For the problem of easy damage to the control circuit, on the basis of vibration test, temperature test, function test, and life test, the qualified matching components are screened out and the parameters are optimized. In short, in the development process of the electric pipe cutting machine, there should be more tests, more field tests, and attention to details.
The support roller swings back and forth during the pipe bending process: the angle between the steel pipe and the horizontal plane is usually designed to be zero. Due to manufacturing errors and various elastic deformations in the pipe bending process, the angle cannot be ideal zero. When moving forward, the forward deformation of the support roller increases, and the included angle also increases. When the steel pipe is bent forward or backward during the bending process, the bending support roller will swing back and forth during the working process. Improving the rigidity of the support rollers and ensuring the lubrication of the rollers can make the swing close to zero.
Bend pipes should pay attention to the perfect working appearance while achieving good working benefits. How to better improve the aesthetics of the laser pipe cutting machine process? The specific analysis is as follows:
1. Use a wooden wedge to firmly block one end of the steel pipe, set it up (note: leave it outside for easy extraction), and sieve the sand that has been fried with fire (the particle size should not be too large or too large). ) Good construction sand is appropriate) Slowly pour in the funnel while it is hot, and beat the pipe wall with a hammer while pouring, so that the dry sand is fully filled, and then squeeze it tightly with another wooden wedge until it is dry . So far the sand has had no chance to loosen in the tube.
2. On the workbench, take a large sample of the elbow: the radius of the outer circle is 50+OD/2, the inner diameter is 50-OD/2, the elbow is spot welded, and the boiling is stopped to prevent excessive or insufficient boiling.
3. Simmer slowly, or use a steam torch to bake slowly. Slow fire and low heat are relatively simple, just slow down the fire, but if you use a steam torch to simmer, you should pay attention to the slow fire of the non-standard elbow section by section, and pay attention to the bottom of the platform next to the part must be baked to the same heat, otherwise it will be stuffy flat!
4. In case of under-stewing (insufficient angle) or over-cooking (high angle), it can be corrected by pouring cold water on the inside or outside of the fish fillet and heating it, and vice versa.
Precautions for laser pipe cutting machine: The sand must be fried with fire, the purpose is to remove the moisture inside and prevent the elbow from exploding when it catches fire.