Thermal Stress of Plate and Pipe Occurred during Dipping in the Molten Zinc Bath

Liquid Metal Embrittlement of Welded Joint of Steel during Hot Dip Galvanizing (Report 2)

Abstract

In previous report, the effect of welding factors on the critical stress for LME-cracking of steel was examined. In addition, because of preventing the crack, it is necessary to study the behavior of thermal stress and residual stress during dipping in the molten zinc that cause the crack in steel structure.
In this report, the distribution of temperature and thermal stress during dipping simple plate and pipe in the molten zinc were analyzed. The results are as follows.
(1) Maximum tensile thermal stress, (σ_t)max occurred at the lower side of plate and pipe, and caused
LME-cracking at this position.
(2) (σ_t)max increased as plate width is large and plate thickness is small. And (σ_t)max increased as pipe diameter is large.
(3) For the plate and pipe, (σ_t)max increased as dipping velocity is small.