Internal surface quality of seamless steel pipe-Boiler Tubes,Heat-Exchanger Tubes,Superheater Tubes,Supplier,Beite

Internal surface quality of seamless steel pipe

Internal surface quality of seamless steel pipe

How to improve the inner surface quality of seamless steel pipe

1. In order to avoid scarring defects in hot continuous rolling seamless steel pipes, first learn to use deoxidizers. The oxides must be in a molten state when the mandrel is pre-pierced. Its strength and other strict requirements. The particle size of the deoxidizer powder is generally required to be about 16 mesh.

2. The content of sodium stearate in the deoxidizer must be more than 12%, so that it can burn fully in the capillary cavity. According to the inner surface area of the capillary to determine the amount of deoxidizing agent sprayed, generally 1.5-2.0g/dm2, the amount of deoxidizing agent sprayed by capillary of different diameters and lengths is different.

3. Secondly, reasonably set the injection process parameters of seamless steel pipes. The injection pressure should match the diameter and length of the capillary to ensure that the purging is strong and the combustion is sufficient, and the incompletely combusted deoxidizer cannot be blown away from the capillary by the airflow. The purge time should be adjusted according to the direct and length of the capillary, and the standard is that no metal oxide suspended in the capillary is blown out.

4. The nozzle height should be adjusted according to the capillary diameter to ensure good alignment. The nozzle should be cleaned once per shift, and the nozzle should be removed for cleaning after a long-term shutdown. In order to ensure that the deoxidizer is evenly purged on the inner wall of the capillary, an optional device is used in the spray deoxidizer station, and is equipped with a rotating air pressure.

5. In addition, lubricate the mandrel. In order to increase the temperature of the mandrel, only one cooling water cooling method can be adopted. The temperature of the mandrel must be strictly controlled during the production process to ensure that the surface temperature of the mandrel is 80-120°C before spraying lubricant, and the temperature of the mandrel cannot be higher than 120°C for a long time to ensure that the lubricant on the surface is dry and dense before pre-wearing. , The operator should always check the lubrication condition of the mandrel.