M. Sabzi, S. Moeni Far, E. Najafi Birgani,
Volume 1, Issue 1 (1-2016)
Abstract
In this investigation, the effect of heat input of SMAW process on the corrosion behavior of Hadfield steel weld joints was investigated. For this purpose, 4 annealed sheets with thickness 25 mm prepared from Hadfield steel and then welding applied by SMAW process with 6.75 and 11.25 kJ/mm heat input values. For corrosion behavior evaluation of base metal and weld metal areas, potentiodynamic polarization and electrochemical impedance spectroscopy methods were used in the 3.5% NaCl solution. The result of corrosion tests indicated that by increasing the heat input in the SMAW process, the corrosion resistance in the weld metal were reduced. It was also found that in both heat input values, base metal had more corrosion resistance compared to weld metal.
Mehdi Asle Taghipour, Reza Dehmolaei, Seyed Reza Alavi Zaree, Mohammad Reza Tavakoli Shoushtari,
Volume 7, Issue 1 (8-2021)
Abstract
The microstructure and mechanical properties of HSLA-100 steel weld joints was investigated. Welding with three heat input of 0.820, 1.176 and 1.392 kJ / mm was performed using E12018 electrode. Microstructural studies were performed using scanning electron and optical microscopes. The mechanical properties of welded joints were evaluated by impact and microhardness tests. Microstructural studies showed that with increasing the heat input, the amount of acicular ferrite in the weld metal decreased and the amount of polyhedral and quasi-polygonal ferrite increased. It was found that with increasing the heat input, the amount of layered bainite in the heat affected zone increased and the amount of granular bainite decreased. Due to the decrease in the amount of acicular ferrite in the weld metal microstructure with increasing inlet temperature, the amount of hardness and impact energy decreased. The results showed that the increase in heat input due to the reduction of the acicular ferrite of the weld metal and the dissolution of precipitates in the coarse grain heat affected zone has caused a decrease in hardness in these zones. It was found that with increasing the heat input due to decreasing the acicular ferrite, the impact energy of the weld metal decreased by 29% (from 45 joules at an heat input of 0.82 to 32 joules at an heat input of 1.392 kJ / mm). It was found that at all heat inputs, the impact energy of the base metal is greater than the impact energy of the weld metal.
