1 The State Key Laboratory of Refractories and Metallurgy, Hubei Province Key Laboratory of Systems Science on Metallurgical Processing, International Research Institute for Steel Technology, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China 2 Wuhan Second Ship Design and Research Institute, Wuhan 430064, Hubei, China 3 Department of Metallurgical and Materials Engineering, University of Texas at El Paso, El Paso, TX 79968, USA
Effects of Zr addition on microstructure and toughness of simulated CGHAZ in high-strength low-alloy steels
1 The State Key Laboratory of Refractories and Metallurgy, Hubei Province Key Laboratory of Systems Science on Metallurgical Processing, International Research Institute for Steel Technology, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China 2 Wuhan Second Ship Design and Research Institute, Wuhan 430064, Hubei, China 3 Department of Metallurgical and Materials Engineering, University of Texas at El Paso, El Paso, TX 79968, USA
摘要 The effect of Zr addition (0.005, 0.013, and 0.054 wt.%) on the microstructure and toughness of simulated coarse-grained heat-affected zone in high-strength low-alloy steels was revealed using a Gleeble 2000 thermal simulator. It was observed that elongated MnS inclusions were formed in the lowest Zr-containing steel, while only pure equiaxed ZrO2 existed in the 0.054Zr steel (Zr content of 0.054 wt.%). Complex oxide–sulfide inclusions (ZrO2 ? MnS) with size of (1.40 ± 0.25) lm were formed in 0.013Zr steel (Zr content of 0.013 wt.%). The complex inclusions refined the prior austenite grain, and the nucleation of acicular ferrite was promoted compared to those of 0.005Zr steel (Zr content of 0.005 wt.%) and 0.054Zr steel. Consequently, the 0.013Zr steel possessed superior low-temperature impact toughness in relation to 0.005Zr and 0.054Zr steels. Thus, moderate Zr addition can be considered as an effective method to refine the structure and improve the mechanical properties of the coarse-grained heat-affected zone.
Abstract：The effect of Zr addition (0.005, 0.013, and 0.054 wt.%) on the microstructure and toughness of simulated coarse-grained heat-affected zone in high-strength low-alloy steels was revealed using a Gleeble 2000 thermal simulator. It was observed that elongated MnS inclusions were formed in the lowest Zr-containing steel, while only pure equiaxed ZrO2 existed in the 0.054Zr steel (Zr content of 0.054 wt.%). Complex oxide–sulfide inclusions (ZrO2 ? MnS) with size of (1.40 ± 0.25) lm were formed in 0.013Zr steel (Zr content of 0.013 wt.%). The complex inclusions refined the prior austenite grain, and the nucleation of acicular ferrite was promoted compared to those of 0.005Zr steel (Zr content of 0.005 wt.%) and 0.054Zr steel. Consequently, the 0.013Zr steel possessed superior low-temperature impact toughness in relation to 0.005Zr and 0.054Zr steels. Thus, moderate Zr addition can be considered as an effective method to refine the structure and improve the mechanical properties of the coarse-grained heat-affected zone.
Jin-wei Lei,Kai-ming Wu,Yu Li, et al. Effects of Zr addition on microstructure and toughness of simulated CGHAZ in high-strength low-alloy steels[J]. Journal of Iron and Steel Research International, 2019, 26(10): 1117-1125.
2019, Vol. 26 
