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How to Control Surface Defects of Q355B Seamless Steel Pipes
Dec 29, 2021
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The material product structure of Q355B seamless steel pipes, China's high-end equipment, is low-end. Some high-end equipment and core components with key basic steel materials rely heavily on imports. The key technology is controlled by others, such as special corrosion resistant oil well pipes, marine corrosion resistant steel, high-speed railway axles, bearing steel, high standard die steel and other key steel products. These products are still not satisfied with the needs of the market. They need to be vigorously developed.
The product development does not connect well with the downstream market demand.
The key development of the material of Q355B seamless steel pipes involves the cooperation between many equipment manufacturing and steel production enterprises, universities and research institutes. However, loose cooperation among Chinese enterprises lacks collaborative innovation ability. Product development is not closely combined with the actual needs of user enterprises, which seriously hinders the development of key basic steel for high-end equipment.
Most of China's iron and steel enterprises' production process control level is not high enough. The production management control index loose. It resulted in the quality fluctuations of domestic iron and steel products, especially high-quality steel products batch. In recent 10 years, a number of state-owned large and medium-sized iron and steel enterprises in China have introduced world-class production equipment. The whole equipment level of steel enterprise has entered into the world's advanced ranks, but the control ability of the enterprise equipment is insufficient. Many key production processes of autonomous control level are not high. The production technical personnel lack innovation ability. It results in that high levels of equipment cannot produce high quality products.
Relevant standards can not adapt to the rapid development of the steel industry. In addition, there are enterprises fine management and low production level, production technology level behind the level of equipment phenomenon.
1. Oxide removers
The oxide is required to be in a molten state when the mandrel is pre-penetrated. Its strength needs strict requirements.
1) The powder size of oxide removers is generally required to be about 16 meshes.
2) The content of sodium starate in the oxide remover should reach more than 12%, so that it can be fully burned in the hair tube cavity.
3) According to the surface area of the capillary pipe to determine the amount of oxide removal agent spray, it is generally 1.5-2.0g/dm2. Different diameters and lengths of the capillary pipe spray oxide removal dose are different.
2. The parameters of the spraying process
1) The injection pressure should be matched with the diameter and length of the capillary pipes to ensure that the purge is powerful and the combustion is sufficient. No incomplete combustion of the oxide remover can be blown away from the capillary pipe by the airflow.
2) The blowing time should be adjusted according to the direct and length of the capillary pipe, and the metal oxides without suspension in the capillary pipe should be blown out again as the standard.
3) The height of the nozzle should be adjusted according to the diameter of the capillary to ensure good alignment. The nozzle should be cleaned once for each shift, and the nozzle should be removed for cleaning during long downtime. The optional device is used at the spraying oxide remover station and equipped with rotating air pressure in order to ensure that the oxide remover is blown evenly on the inner wall of the capillary pipe.
3. Mandrel lubrication
It is learned that the mandrel lubrication effect is not good or the temperature of mandrel lubricant is too low. Finally, it will produce an inner scar. The cooling water can be used only once in order to increase the temperature of the mandrel. In the production process, the temperature of the mandrel should be strictly controlled to ensure that the surface temperature of the mandrel. The temperature of the mandrel should not be higher than 120℃ for a long time to ensure that the lubricant on the surface is dry and dense before pre-wearing. The operator should often check the lubrication status of the mandrel.
The product development does not connect well with the downstream market demand.
The key development of the material of Q355B seamless steel pipes involves the cooperation between many equipment manufacturing and steel production enterprises, universities and research institutes. However, loose cooperation among Chinese enterprises lacks collaborative innovation ability. Product development is not closely combined with the actual needs of user enterprises, which seriously hinders the development of key basic steel for high-end equipment.
Most of China's iron and steel enterprises' production process control level is not high enough. The production management control index loose. It resulted in the quality fluctuations of domestic iron and steel products, especially high-quality steel products batch. In recent 10 years, a number of state-owned large and medium-sized iron and steel enterprises in China have introduced world-class production equipment. The whole equipment level of steel enterprise has entered into the world's advanced ranks, but the control ability of the enterprise equipment is insufficient. Many key production processes of autonomous control level are not high. The production technical personnel lack innovation ability. It results in that high levels of equipment cannot produce high quality products.
Relevant standards can not adapt to the rapid development of the steel industry. In addition, there are enterprises fine management and low production level, production technology level behind the level of equipment phenomenon.
1. Oxide removers
The oxide is required to be in a molten state when the mandrel is pre-penetrated. Its strength needs strict requirements.
1) The powder size of oxide removers is generally required to be about 16 meshes.
2) The content of sodium starate in the oxide remover should reach more than 12%, so that it can be fully burned in the hair tube cavity.
3) According to the surface area of the capillary pipe to determine the amount of oxide removal agent spray, it is generally 1.5-2.0g/dm2. Different diameters and lengths of the capillary pipe spray oxide removal dose are different.
2. The parameters of the spraying process
1) The injection pressure should be matched with the diameter and length of the capillary pipes to ensure that the purge is powerful and the combustion is sufficient. No incomplete combustion of the oxide remover can be blown away from the capillary pipe by the airflow.
2) The blowing time should be adjusted according to the direct and length of the capillary pipe, and the metal oxides without suspension in the capillary pipe should be blown out again as the standard.
3) The height of the nozzle should be adjusted according to the diameter of the capillary to ensure good alignment. The nozzle should be cleaned once for each shift, and the nozzle should be removed for cleaning during long downtime. The optional device is used at the spraying oxide remover station and equipped with rotating air pressure in order to ensure that the oxide remover is blown evenly on the inner wall of the capillary pipe.
3. Mandrel lubrication
It is learned that the mandrel lubrication effect is not good or the temperature of mandrel lubricant is too low. Finally, it will produce an inner scar. The cooling water can be used only once in order to increase the temperature of the mandrel. In the production process, the temperature of the mandrel should be strictly controlled to ensure that the surface temperature of the mandrel. The temperature of the mandrel should not be higher than 120℃ for a long time to ensure that the lubricant on the surface is dry and dense before pre-wearing. The operator should often check the lubrication status of the mandrel.
