|
|
Effect of Mo content on nano-scaled particles, prior austenite grains and impact toughness of CGHAZ in offshore engineering steels |
De-kun Liu, Jian Yang, Yin-hui Zhang, Long-yun Xu1 |
1 State Key Laboratory of Advanced Special Steel, School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China |
|
|
Abstract The effect of Mo on nano-scaled particles, prior austenite grains and impact toughness of coarse-grained heat-affected zone (CGHAZ) in offshore engineering steels with Ca deoxidation was studied. The heat-affected zone (HAZ) toughness of Mo16 steel is obviously higher than that of Mo8 steel at all the heat inputs of 50, 100, 150 and 200 kJ/cm, with HAZ toughness of both steels decreased with increasing the welding heat input. When the Mo content is increased from 0.08 to 0.16%, the size of nano-scaled particles in HAZ is decreased from 18 to 15 nm, and their number density is increased from 0.7 to 0.9 μm-2. Thus, the Zener pinning force is increased, and the prior austenite grain size (PAGS) is decreased, leading to the improved HAZ toughness. Microstructural characterizations show that the nano-scaled particles in both steels are Ti(C, N) with the solute elements of Nb and Mo. The calculated critical particle size of TiN is 10.2 and 8.4 nm in Mo8 and Mo16 steels at 1350 °C, and the particles larger than the critical size are stable during the welding process. From the Zener pinning force calculation, Ti(C, N) particles play the more important role in the pinning effect on the prior austenite grain growth. Based on the regression analysis by the MATLAB results, the predicted values of PAGS at different heat inputs are well fitted with the experimental data.
|
|
|
|
|
Cite this article: |
De-kun Liu,Jian Yang,Yin-hui Zhang, et al. Effect of Mo content on nano-scaled particles, prior austenite grains and impact toughness of CGHAZ in offshore engineering steels[J]. Journal of Iron and Steel Research International, 2022, 29(5): 846-858.
|
|
|
|
[1] |
Ting-wei Ma, Xian-chao Hao, Ping Wang. Effect of heat treatments on Charpy impact properties of 15Cr12MoVWN ferritic/martensitic steel[J]. JOURNAL OF IRON AND STEEL RESEARCH,INTERNATIONAL, 2022, 29(3): 512-518. |
[2] |
Xi-kou He, Chang-sheng Xie, Li-jun Xiao, Ying Luo, Di Lu, Zheng-dong Liu, Xi-tao Wang. Microstructure and impact toughness of 16MND5 reactor pressure vessel steel manufactured by electrical additive manufacturing[J]. JOURNAL OF IRON AND STEEL RESEARCH,INTERNATIONAL, 2020, 27(8): 992-1004. |
[3] |
Xi‑kou He, Zhi‑qiang Yang, Zhen Wang, Shi‑bin Qiao, Zheng‑dong Liu. Effect of Mn content on microstructure, tensile and impact properties of SA508Gr.4N steel for reactor pressure vessel[J]. JOURNAL OF IRON AND STEEL RESEARCH,INTERNATIONAL, 2020, 27(4): 461-470. |
[4] |
Jun-hui Li, Hong-hong Wang, Qiang Luo, Li Li, Chao Sun, R.D.K. Misra . Correlation between microstructure and impact toughness of weld heat-affected zone in 5 wt.% manganese steels[J]. JOURNAL OF IRON AND STEEL RESEARCH,INTERNATIONAL, 2019, 26(7): 761-770. |
[5] |
Tian-hai Wu, Jian-jun Wang, Hua-bing Li, Zhou-hua Jiang, Chun-ming Liu, Hong-yang Zhang. Effect of heat input on austenite microstructural evolution of simulated heat affected zone in 2205 duplex stainless steel[J]. JOURNAL OF IRON AND STEEL RESEARCH,INTERNATIONAL, 2019, 26(5): 435-441. |
[6] |
Tong-bang An, Jin-shan Wei, Lin Zhao, Ji-guo Shan, Zhi-ling Tian. Influence of carbon content on microstructure and mechanical properties of 1000 MPa deposited metal by gas metal arc welding[J]. JOURNAL OF IRON AND STEEL RESEARCH,INTERNATIONAL, 2019, 26(5): 512-518. |
|
|
|
|