Abstract
Back heating method is proposed for angular distortion decreasing technique. Back heating is expected for angular distortion decrease to the following two effects; that is, bending in the opposite direction and homogenization of temperature distribution through thickness direction. Best condition of temperature distribution control for angular distortion decrease has been evaluated with numerical simulation. Back heating source is appropriately arranged to welding heat source, then, angular distortion is decreased more effective than the above-mentioned effects, and perfectly decreased by back heating of ten percent to welding heat input. In back heating, angular distortion can be decreased by the change in generation behavior of inherent strain according to nonconventional temperature history. Angular distortion decreasing technique is effective in any condition concerning heat input parameter and the best condition concerning multiple-heat-source arrangement is decided to be dependent on the size of mechanical molten pool.
