METHOD FOR PREVENTING HOT-DIP GALVANIZING CRACKING

• Main Authors: MASUDA KAZUHIRO, INOUE HISASHI, YOSHIDA KOTARO, KANETANI KEN
• Format: Patent
• Language: English
• Published: 15.02.1991
• 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

PURPOSE:To prevent the cracking of hot dip galvanizing by previously thermally spraying a metal having a melting point higher than that of zinc on the weld zone of a structural member of a steel structure to be subjected to hot-dip galvanizing after welding. CONSTITUTION:In a steel structure to be subjected to hot-dip galvanizing, a metal having a melting point higher than that of zinc is thermally sprayed on a weld zone prior to hot-dip galvanizing after the assembly of a structural member by welding. At this time, zinc can be further thermally sprayed, after the application of thermal spraying with the metal having a melting point higher than that of zinc to the weld zone, on the resulting sprayed deposit. As the metal having a melting point higher than that of zinc, a metal consisting of one or more kinds among iron, copper, Ni, and Al or a metal consisting of either or both of Al and Mg and zinc can be cited. By this method, the contact of a cracked zone with molten zinc, as the most primary factor in causing cracking, can be reduced or removed, and, as a result, cracking can be perfectly prevented.