Stress corrosion cracking of structural steels immersed in hot-dip galvanizing baths

摘要: Abstract Failures during hot-dip galvanizing are occasionally, but they important because of the high responsibility evolved structures. Traditionally two processes have been related with this phenomenon: liquid metal assisted cracking and hydrogen embrittlement. Hydrogen influence is discarded after concentration tests performed in paper. Besides, crack characterization on steel CT specimens which immersed galvanization bath Zn, 1.1% Sn 0.1% Bi at 450 °C detailed. The main obtained results were three: 1. value threshold stress intensity factor, K th , lowest to produce cracking; 2. subcritical propagation rate (d a /d t ) II ; 3. failure assessment diagram (FAD) for different load conditions. Microscopy revealed intergranular existence an intermetallic compound, FeSn, tips. As final result, authors propose key points qualitative model consists first step accumulation Pb tips, second production FeSn due accumulated stresses.