The Improvement of Mechanical Properties of the Incoloy ۸۲۵ Weld Metal by Applying Electromagnetic Vibration

In this study, the effect of applying electromagnetic vibration simultaneously along with welding to improve the mechanical properties of the Incoloy ۸۲۵ superalloy weld metal was investigated. The samples were welded by the GTAW method and the simultaneous application of electromagnetic vibration under voltages from zero to ۳۰ volts. The impact toughness and hardness of the weld metals produced by different voltages were measured. The microstructure of base and weld metals was investigated by an optical microscope and SEM. Microstructural studies showed that the weld metal has a fully austenitic matrix with fine precipitates on the grain boundaries and within the grains. It was found that the application of electromagnetic vibration by the fragmentation of the dendrite tips and their entry to the weld metal molten pool contribute to the increasing of heterogeneous nucleation and therefore grain refinement. The result of impact and hardness tests depicted that by applying the electromagnetic vibration the impact toughness and hardness of the weld metal are increased from ۲۷.۷ to ۳۵.۳ jols and from ۲۰۵.۵ to ۲۵۷.۷ Vickers, respectively. It was found that electromagnetic vibration improves the hardness and impact energy of the weld metal by affecting the parameters, refined equiaxed dendrites, structure within grains and better distribution of precipitates.

کلیدواژه ها:

Incoloy ۸۲۵ ، welding ، Electromagnetic Vibration ، Mechanical Properties ، dendrites fragmentation