Temperature,macrostructure and hardness in high strength low alloy steel welds

Abstract

A series of welds have been fabricated in high strength low alloy steel (HSLA100) plate by gas metal arc welding at heat inputs of 1.0, 1.6 and 2.2 kJ mm^-1. Slices from the welds were then polished and the macrostructure was observed. Hardness maps were then determined over the entire weld zone, including the heat affected zone and the base plate. Correlations were then made between the hardness maps and the macrostructure. A bead on plate weld was made using the same heat inputs and was used to determine the temperature regimes in the weld as well as thermal profiles of the weld region. Relationships showing good correlations were observed between the various microstructures, the macrostructure, the calculated thermal profiles, and the hardness values.