Method for improving uniformity of coating layer of hot dip galvanized steel pipe

• Main Authors: XIONG JUNBO, LIU XIN, YANG WEIFANG, ZHANG JIE, LIU PENG, ZHONG HAIFENG, LI YUANPENG, GAO ZHIQIANG, SHEN YANG, JIANG SHEMING, XI ZHONGGE, ZHANG ZIYUE
• Format: Patent
• Language: Chinese; English
• Published: 24.08.2018
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

The invention relates to a method for improving the uniformity of the coating layer of a hot dip galvanized steel pipe, and belongs to the technical field of galvanized steel pipes. The method comprises the following steps: removing the steel pipe from a galvanizing liquid, and allowing the steel pipe to penetrate into an external blowing device in an axial direction; introducing heated air or gasinto the external blowing device to perform external blowing on the steel pipe with the galvanizing liquid on the surface; producing the finished galvanized steel pipe product from the externally-blown steel pipe; measuring the thickness of the coating layer of the galvanized steel pipe; adjusting the gas pressures of the upper blowing chamber and the lower blowing chamber of the external blowingdevice according to the measurement result; and massively producing the galvanized steel pipe. The internal of the external blowing device is divided into the upper blowing chamber and the lower blowing chamber, and the gas w