Pocks and pits are common surface quality problems in the manufacture of
seamless tubes. For pits and pits when they are delivered, if this happens, many manufacturers will say that it is due to the quality of the original round steel plant. cause this problem.
The selection of round steel may have an impact on the manufacture of seamless tubes, but it is not the final deciding factor. The real reason lies in this process - perforation
1. Many manufacturers have unreasonable selection of perforated furnace equipment. Shorter perforated furnaces make the round steel unable to be heated evenly, resulting in high temperature deviation inside and outside, which affects the change of structure and causes pitting and pits.
2. The setting of the plug, if the inferior plug is used, the water sprayed from the plug directly contacts the inner and outer surfaces of the high-temperature steel pipe, and the steel pipe encounters a large temperature difference, thereby forming internal and external defects, that is, warped skin or pits.
3. In the perforation furnace equipment, small factories do not pay attention to environmental protection and temperature control. For different steel grade seamless tubes, it is impossible to adjust the temperature adaptability in time, and then change the steel grade surface and internal structure, resulting in warped skin, concave The occurrence of pit phenomenon.
Pay attention to the selection of piercing furnace equipment. Excellent equipment can avoid pitting and pits in the production process of seamless steel tubes, speed up production, and reduce a certain delivery cycle. Longer piercing furnaces can make round steel evenly heated. Low temperature deviation inside and outside. Secondly, using a high-quality plug, although the cost is high, the perforated capillary has no warping skin and pits, which eliminates the surface quality problems that may be encountered in post-processing from the source. In the end, good natural gas settings are used, which is environmentally friendly and pollution-free. Different steel grades will have different temperature controls to avoid warping and pitting.
