Effect of normalizing process on mechanical properties of submerged-arc weldment

Abstract EN

Submerged arc welding is carried out and efficient metal- joining process widely used in great importance in many industrial applications, structures of ships, storage tanks and agriculture equipment's.

Low alloy steel used under welding conditions which are, (560 Amp) welding current, (42cm / min) welding speed, (3.25mm) wire diameter, direct current straight polarity (DCSP) with the joint geometry of single–Vbutt joint and weld one pass are used for plate of thickness 16mm.

After welding, the components have be submitted to a normalization heat treatment in order to recover the original mechanical properties of the welds.

In this work two different filer metals both in the as welded condition and after normalizing heat treatment have been studied.

Optical microscopy was used to observe the weld microstructure.

Tensile and Charpy V toughness testing and micro hardness measurements were used to evaluate the mechanical properties of joint.

Results show that normalizing reduces the original columnar structure in the as welded condition to an equiaxial structure.

It was observed a high decrease in the tensile properties specially the yield strength after normalizing.

In respect of toughness, the normalizing heat treatment was observed to increase the Charpy V energy.