As advanced steels are developed and used in welded structures, performance of weldments is one of prime issues as well as cost performance of welding. Demands for high-performance steel welds have been increasing in various application areas, not only in shipbuiding and offshore sructures but also in building construction and engineering works. Improvement in low-temperature toughness and stress-corrosion-cracking resistance of welds is critical to recent oil and gas exploitation and gathering in severe environments. Large heat-input welding and higher-strength welds are required with increasing the size of welded structures, while fire-resisting properties of steels and their welds are important for high-rise buildings.
The present paper reviews a recent progress of welding technology for low alloy steels in light of the above trend. Effect of alloying elements and microstructures on weld performances are outlined, and significance of controlling alloy and phase chemistries in the welds is discussed in order to meet the increasing demands for improved weld performances.