Abstract
Welding is a widely used process that requires continuous developments to meet new application demands of mechanical projects under severe conditions. The homogeneity of metallurgical and mechanical properties in welded joints is the key factor for any welding process. The applications of external magnetic fields, mechanical vibration, and ultrasound are the fundamental steps to achieve success in improving these properties. The present work aimed at determining suitable processing conditions to achieve the desired balance between metallurgical and mechanical properties of 304L steel in TIG (Tungsten Inert Gas) welding under the application of an external magnetic field. The microstructural characteristics of the weld bead were analyzed by optical microscopy (OM) and scanning electron microscopy (SEM). In order to evaluate the mechanical properties of the welded specimen, its Vickers microhardness map and Charpy impact energy at −20 °C were obtained. In addition, corrosion tests were carried out in the saline medium to compare the corrosion resistance of the joint with that of the base metal and that without the magnetic field. It was found that the external magnetic field decreased the percentage of delta ferrite, improved the filling of the weld pool with the weld metal, and decreased the primary and secondary dendritic spacings. The Vickers microhardness value under the magnetic field was found to be lower than that without the magnetic field, and the Charpy test showed no significant variation in energy absorption. Moreover, the welded joint produced under the external magnetic field manifested less resistance to corrosion.
Highlights
In recent years, welding has attracted widespread attention in mechanical and construction projects owing to its several advantages, including high energy density, good geometry, and high efficiency [1,2,3,4,5]
It was found that fusion zone (FZ) and HAZ were composed of austenite grains and delta ferrite [13]
HAZ was composed of coarse grains and grains stretched to FZ
Summary
In recent years, welding has attracted widespread attention in mechanical and construction projects owing to its several advantages, including high energy density, good geometry, and high efficiency [1,2,3,4,5]. According to Baldan et al [5], the main problems during welding are root dropout, overlap, lack of penetration, undercut, lack of fusion, and cracks Different approaches, such as welding with mechanical agitation, ultrasound, and an external magnetic field, have been employed to minimize or avoid these problems. The energy obtained under the application of mechanical vibration was responsible for producing a load that overlapped the existing stress pattern, inducing a movement within the weld pool This welding process is not always recommended because mechanical vibration can cause harmful effects on surrounding operations. Among the different approaches to reduce welding defects, investigations of welding with an external magnetic field were performed owing to its practicality, low financial cost, and improvements in the metallurgical and mechanical properties of the weld.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
