摘要：At start-up operation of hot dip galvanizing baths to galvanize steel products, several leakage accidents of liquid zinc due to the damage at the vicinity of welded parts between side and bottom plates have been reported... The authors reported in the previous paper that the material of bottom plate of the damaged bath were examined by metal structure observation, SEM observation, EPMA analysis, hardness measurement and tensile test and it was concluded no problems were found in the material... In addition, they guessed the effect of liquefied metal soaking into grain boundary of the metal as a cause of the damage because lead and zinc were found inside of the crack... This paper, following previous one,reports that the heat affected zone of applied material at the damaged part does not have any peculiarity according to the results of Charpy impact test and maximum hardness test for a heat affected zone of the new sample of the same virgin material. .. Further it specifies the part where crack occurs by examining crack profile of newly taken sample and the sample applied in the previous paper.
