Influence of Localized Induction Preheating on Metallurgical Characteristics of Welded Joints

Abstract

One of the purposes of welding preheating is to decrease cooling rate of the joint to be welded, with consequent minimization of brittle phases formation. This practice is usually performed in a relatively large area around the joint, eventually causing undue changes in base metal mechanical and metallurgical properties, beyond to waste energy and time. Therefore, in this work an inductive heating equipment was used to locally heat the zone to be welded, aiming to evaluate the formed microstructure and the hardness profile found for the varied parameters. The use of preheating was effective in reducing cooling rates and consequently the proportion of brittle phases and maximum microhardness of the welded joint.

Key-words:
Welding; Inductive heating; Preheating