Abstract

Experiment and results. Single and multi- run HSLA steel welds were produced by MMAW process in flat and vertical up welding position. In this context, further work was carried out in parent plates 6.3, 8, 10 and 12.7mm thickness in bead on plate and Butt welds with E7018 LT and E 8018 (higher Ni content) electrodes. The microstructural study results in these welds are as follows: [1]. Flat welding position, 6.3 and 8mm thickness in bead on plate and Butt welds with lower heat input, fast cooling rates, shorter available time distance within initial austenitic temperature range, the weld microstructure consisted of pro eutectoid ferrite and inter granular acicular ferrite within pro eutectoid (prior) austenite grains.