10.30684/ etj.29.8.11


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 equipments. 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 microhardness 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.