抄録
Crack nucleation sometimes occurs at the underhead fillet of a bolt when it is galvanized. The phenomenon is generally known as liquid zinc embrittlement, but the effect of the pretreatment such as the acid pickling on liquid zinc embrittlement is not well known.
In the present study, to investigate the effect of the pretreatment on liquid zinc embrittlement, the observations of the crack on the longitudinal section and the fracture surface at the underhead fillet of bolts which were subjected to various pretreatments were performed by using an EPMA and an optical microscope. The main results are as follows:
(1) The acid pickling accelerated crack nucleation.
(2) The value of pH in fluxing affected the crack nucleation.
(3) The shot blasting had the effect of preventing crack nucleation.
