Press Release: December 14, 2020
The factors that affect the coating of seamless steel pipes mainly include the following four points: The passive film of seamless steel pipes is a suppressed metastable structure in thermodynamics, and its maintenance is related to the medium in the environment. But no matter what kind of environment it is used in, it must be regularly cleaned to remove harmful substances attached to the surface.
Chloride ions are extremely harmful to the coating of seamless steel pipes. We must strictly control the content of chloride ions in the passivation solution during the process of stopping the passivation of the external surface. Many chemical materials for passivation have limited requirements for chloride ions. In the configuration of passivation liquid and cleaning water, there are also strict water quality requirements for chloride ions to ensure that the passivation waste does not contain chloride ions.
The low nickel content in seamless steel pipes has low passivation performance, so the martensite content and the content of chromium and nickel have a great influence on the passivation performance of the rectangular tube. The more lubricated the surface of stainless steel, the lower the roughness, the more difficult it is for foreign matter to adhere, and the corrosion will be reduced to the lowest point. Therefore, the surface of the rectangular tube should be finished as much as possible. In addition, the cleaning after passivation should be stopped carefully, so that the remaining acid can promote the anode response, maintain the integrity of the film, and ensure that the appearance of corrosion resistance is strengthened.
In the production and transportation of seamless steel pipes, oil stains will inevitably adhere to the surface, which will affect the quality of rust removal and phosphating, and reduce the bonding force between the coating and the substrate. Mainly use organic solvents to dissolve saponified and unsaponified oils to remove oil stains. Commonly used organic solvents are ethanol, gasoline for cleaning, toluene, carbon tetrachloride, trichloroethylene, etc. Among the more effective solvents are carbon tetrachloride and trichloroethylene, which will not burn and can be used for degreasing at higher temperatures.
Tips: A53 Grade B Seamless is our most popular product under this specification and A53 pipe is commonly dual certified to A106 B Seamless pipe.
ASTM A53 Grade B is the material under the American steel pipe standard, API 5L Gr.B is also the American standard material, A53 GR.B ERW Pipe refers to the electric resistance welded steel pipe of A53 GR.B; API 5L GR.B Welded refers to the material Welded steel pipe of API 5L GR.B.