抄録
Liquid metal embrittlement cracking (LMEC) of steels and welds in hot dip galvanizing process was studied. Commercial weldable structural steels were exposed to Y-Groove cracking test and sustained load test in molten zinc, and the effect of metallugical properties on LMEC sensitivity and fracture stress were investigated.
Results obtained are summarized as follows.
(1) In both tests the welds suffered from intergranular fracture in grain coarsed region of heat affected zone in molten zinc. This behavior corresponds to LMEC of welded steel structures.
(2) LMEC sensitivity of steels and welds, which is expressed by cracking percentage in Y-Groove Cracking Test or liquid zinc embrittlement fracture ratio in Sustained Load Test, is influenced by hardness.
(3) LMEC fracture stress is affected by hardness and grain size of steels and welds.
