Views: 0 Author: Site Editor Publish Time: 2022-01-04 Origin: Site
In order to improve the corrosion resistance of thick-walled steel pipes and prolong the service life of the products, the thick-walled steel pipes need to be pickled and passivated to form a protective film on the surface. Thick-walled steel pipes have high hardenability, good machinability, moderate cold deformation plasticity, and weldability; in addition, the toughness of steel is not much reduced during heat treatment, but it has quite high strength and wears resistance, especially when it is water quenched. It has high toughness; but this steel is highly sensitive to white spots, has a tendency to temper brittleness and overheating sensitivity during heat treatment, has high strength, hardenability, good toughness, small deformation during quenching, and high creep strength at high temperatures And long-term strength
1. Thick-walled steel pipe cutting: According to the actual required pipeline length, metal saws and toothless saws should be used to cut the pipelines. When water welding is used in the cutting process, the raw materials should be protected accordingly. When cutting, fire-resistant and heat-resistant materials should be used as baffles at the two ends of the fracture to catch the sparks and hot molten iron that fall during cutting, so as to protect the raw materials. The original plastic layer.
2. Thick-walled steel pipe connection: After the plastic repair is completed, connect the pipe and the pipe fittings and install rubber pads between the flanges during the connection process, and tighten the bolts to the sealed state.
3. Plastic coating treatment for thick-walled steel pipes: After polishing, use oxygen and C2H2 to heat the pipe mouth outside the pipe until the internal plastic layer is melted, and then the skilled worker will evenly apply the prepared plastic powder to the pipe mouth, Should pay attention to correspondingly to be smeared in place, and the flange plate should be smeared above the water stop line. In this process, the heating temperature should be strictly controlled. If the temperature is too high, bubbles will be generated during the plastic coating process. If the temperature is too low, the plastic powder will not melt during the plastic coating process. The above conditions will produce plastic after the pipeline is put into use. With the phenomenon of layer shedding, the thick-walled steel pipe part of the pipeline was corroded and damaged in the later stage.
4. Thick-walled steel pipe mouth grinding: After cutting, an angle grinder should be used to grind the plastic layer of the pipe mouth. The purpose is to avoid melting or burning the plastic layer during flange welding and destroying the pipe. Use an angle grinder to polish the plastic layer of the nozzle.
Before using thick-walled steel pipes next time, remember to refer to these steps to improve the service life of the product.