RESEARCH AND DEVELOPMENT.

Abstract

Variation in heat input did not affect significantly the composition, microstructure, tensile and hardness properties of the weld deposits and had only a marginal effect on toughness. The best toughness values in the absence of post-weld heat-treatment was associated with fine, acicular ferrite microstructures, containing little or no proeutectoid ferrite. The toughness of vanadium-free weld deposits generally improved after post-weld heat-treatment, although the strength decreased; deposits containing vanadium were embrittled by post-weld heat-treatment and strength was increased due to secondary hardening.