Abstract
Submerged arc welding is often used in the construction of large steel structures such as bridges where weather-resistant steel materials are used because of its high welding efficiency. However, end cracking, which is solidification cracking, may occur at the weld termination. To prevent such cracking, a tab plate is attached to the weld termination to restrain the end of the base metal, but depending on the type of restraint method, end cracking may not be prevented.
In this study, the effects of two types of restraint methods in the tab plate on the occurrence of termination cracking in one-pass submerged arc welding were investigated from both experimental and analysis points of view. Experimental results showed that cracking occurred in the cascade restraint method with a large restraint in the groove, which was initially considered to have a low risk of end cracking. However, simple restraints with small restraint in the groove did not cause end cracking. After confirming that the temperature history, penetration shape, and transverse shrinkage agreed well with the experimental results, hot cracking analysis was used to evaluate end cracking, and it was confirmed that the analysis could reproduce well the trend of cracking risk and the location of cracking that occurred at the weld termination for different restraint methods. In addition, by comparing the amount of bevel shrinkage at the weld termination during cooling, it was confirmed that the amount of bevel shrinkage of specimen B, in which the restraint in the bevel is large, is smaller than that of specimen A, in which the restraint in the bevel is small.
