Effects of heat input on microstructure and mechanical properties of Fe–2Cr–Mo–0.12C steel

Abstract

Thermal simulated specimens with the heat inputs of 20, 50 and 80 kJ/cm were used to investigate the effects of heat input on the microstructure and mechanical properties of the Fe–2Cr–Mo–0.12C pressure-vessel steel. The results indicated that the microstructures in the coarse-grained heat affected zone of tested steels with various heat inputs were mainly consisted of lath martensite and bainite ferrite. As the heat input increased, the fraction of martensite decreased and the bainite ferrite fraction increased. The toughness (tested at −40°C) and hardness for the heat input of 50 kJ/cm were 102 J and 346 HV, respectively, which was attributed to the high-volume fraction (60%) of the high-angle grain-boundary and the fine bainite lath. This paper is part of a thematic issue on Nuclear Materials.

Nuclear Materials

“…For this reason, the article by Kumara et al [4] should be of great interest to readers. The article by Wang et al [5] will be of significant interest to those in the modelling community involved in the prediction of residual stresses in steel welds since, in order to account for the effects of solid-state phase transformations, it is important to obtain reliable estimates for the prior-austenite grain size. Multipass welding of the primary components in a pressurised water reactor subjects the material to significant thermomechanical cycling.…”

Effect of Tempering Temperatures on Tensile Properties and Rotary Bending Fatigue Behaviors of 17Cr2Ni2MoVNb Steel

“…Adding an excessive amount would reduce ductility [7]. The addition of an appropriate amount of Mo contributes to precipitation strengthening and provides phase balance strengthening [8]. In particular, Wang's investigations showed that V can effectively prevent abnormal austenite grain growth in 10 h [9].…”