Post on the Issue of Safety of Steel Structures of Hot Dip Galvanized Structural Components

Abstract

Worldwide, the majority of newly built steel structures are protected against corrosion by hot dip galvanizing. The coating is applied by immersion of steel parts in molten zinc at a temperature around 450°C. Components supplied for coating are characterized by the presence of residual stress inserted into them during their manufacture, from the rolling process, through the forming and welding, optionally through the subsequent straightening. During immersion in molten zinc are the parts exposed to a sudden uneven heating inducting some variable tension usually reaching the yield point of steel. In extreme cases, these effects lead to a disruption of the material integrity. The safety of the steel structures is one of priority questions to which should be found a reliable answer. Detailed knowledge of the stress state of steel exposed to uneven heating from the gradual immersion in molten zinc and of the changes induced in the structure of the material is essential for a thorough analysis of the issue in all the physical and metallurgical patterns and contexts and to formulate reliable conditions under which the risk of crazing relevant reducing the carrying capacity with the dip galvanized steel building components could be eliminated.