Advances in welding metallurgy of steel

AbstractProgress in welding with regard to ferritic, austenitic, and duplex-microstructure grade steels is discussed. In transformable ferritic steels, the influence of second-phase particles on welding behaviour is an important theme and examples given include their effect on: (a) heat affected zone (HAZ) microstructure, hardenability, and toughness; (b) HAZ reheat cracking; (c) weld-metal microstructure and toughness; and (d) weld-pool behaviour during arc welding. The improved quantitative understanding of factors controlling solidification and hydrogen-induced cracking in weld deposits is also discussed. In high-alloy austenitic grades, a greater awareness of the advantages of fabricating low-C grades is noted, together with recognition of the important role of residual stress in the development of intergranular stress-corrosion cracking. Factors controlling the creep properties of austenitic weld metal have been clarified, and methods of producing highly aligned columnar grains in multipass austeniti...