抄録
The local hydrogen concentration in the heat-affected-zone where the root cracking occurred has been investigated using the finite difference method. The effect of groove and weld metal shapes on the local hydrogen concentration was basically examined. It is clear that the local hydrogen related with the cold cracking is not determined by the time factor, but by the thermal factor, namely, throat depth does not become a main factor. The root face, the root angle and the bond line shape are important factors of the local hydrogen concentration.
