Heri Wibowo, M. Noer Ilman, Priyo Tri Iswanto, M. Rifai Muslih
The use of thin plates sections in fabrication of ship hull structures for weight savings is preferable but it tends to produce weld distortion. This current research aims to study distortion and residual stress control methods by combining dynamically controlled low stress no distortion (DC-LSND) and transient thermal tensioning (TTT) techniques. These combined 'in-process' treatments were conducted by quenching the weld metal behind the welding torch using cryogenic liquid nitrogen and simultaneously performing the secondary heating process using flame torches at both sides of the weldline. Subsequently, a number of experiments was carried out as follows: distortion measurement, residual stress measurement, microstructure examination, hardness measurement, tensile test and fatigue test. Results show that combined effect of DC-LSND and TTT treatment can effectively reduce distortion and residual stress which lead to improved fatigue crack growth performance. In addition, changes in strength and hardness of the weld joints are also observed and these are associated with changes in microstructures due to secondary heating and quenching during welding. © December 2017 IJENS.
Department of Mechanical and Industrial Engineering, Universitas Gadjah Mada, Indonesia; Department of Mechanical Engineering Education, Yogyakarta State University, Indonesia; National Nuclear Energy Agency of Indonesia (BATAN), Serpong, Banten, Indonesia
