improvement of mechanical properties and hot cracking susceptibility of 304 stainless steel weld joints with the simultaneous electromagnetic vibration application

The aim of this research was to study the effect of simultaneous vibration application during welding under the voltage range of 0-30 volts on the mechanical properties and hot cracking susceptibility of 304 stainless steel welded joints. The microstructural investigations by optical and scanning electron microscopes showed that electromagnetic vibration application resulted in fragmentation of dendrite tips, increasing of nucleation sites and alteration of solidification structure from columnar to equiaxed structure. Therefore, the final microstructure undergoes grain refinement and extension of equiaxed dendriteic region. Hardness measurement of welded region showed increasing value due to vibration application. The results of Charpy test done on welded specimens revealed that impact energy has been increased from 112 J to 136 j under different electromagnetic vibration intensities. It was also determined that under electromagnetic vibration, weldability was improved, hot cracking susceptibility was decreased and fracture toughness of welded joints under electromagnetic vibration was increased.