The fatigue properties of welded components can be improved by means of post-weld treatments, like TIG dressing or hammering. This article describes the results obtained in the research project “DURIMPROVE”, in which the effects of post-weld treatments on welds in high strength steel were investigated.
Magnetic pulse welding is a new, very innovative but nearly unknown production process. The working principle of the welding process is based on the use of electromagnetic forces to deform and to weld workpieces. Since this sophisticated welding process doesn't use heat to realise the weld, it offers important advantages with regard to the conventional welding techniques!
The workpieces are placed inside a coil. A large amount of energy is compressed and discharged in an extremely short period of time. The high energy flows in the coil, and the discharge of electric energy induces the so-called "eddy currents" in the external workpiece. Both currents (in the coil and in the external workpiece) induce magnetic fields, which oppose each other. The reaction forces between the opposing magnetic fields are forcing the external part towards the internal part at high velocity to cause welding. No protecting atmosphere, filler materials or other aiding materials are necessary. The magnetic pulse welding process is a "cold" welding process, the material does not get warmer than 30°C. Due of this, no heat affected zone is created, and the metal is not degraded. The weld becomes the strongest part of the assembly.