摘要：The objective of this work is to obtain the supper long fatigue life of boxing fillet joints through simple repair welding. Firstly, based on the numerical simulation technology, an elongated bead method was developed and practically all position welding conditions suitable in ship yards were tested. Then, a low transformation temperature (LTT) welding wire having optimal phase transformation characteristics for generation of large compressive residual stresses was designed and manufactured, which is capable to all position welding using the low cost CO2 shield gas. Compared with the conventional fatigue life of boxing fillet joints, the new elongated bead method using the newly manufactured LTT flux cored welding wire extended the fatigue life to more than 10 times at the joint by flat welding and 3-8 times at the joints by overhead welding, horizontal welding and vertical welding, respectively.
