This study investigates weldability of welded joints of SBHS700 based on Y-groove weld cracking test. This study tried to prevent weld cracking: hot cracking and cold cracking by using under-matching welded joints with ultra-low hydrogen weld materials. As a result, although both hot cracking and cold cracking were observed in the tests, any weld crack has not been observed in under-matched welded joints that used ultra-low hydrogen weld materials. Consequently, this study may conclude that it is not necessary for SBHS700 under-matching welded joints having under 32 mm plate thickness using ultra-low hydrogen weld materials to conduct the pre-heating.
