Effect of Si on Microstructure and Mechanical Properties of a 9Cr Ferritic/Martensitic Steel

doi:10.11900/0412.1961.2022.00398

IMR OpenIR

	Effect of Si on Microstructure and Mechanical Properties of a 9Cr Ferritic/Martensitic Steel
	Zhang, Qiankun 1,2; Hu, Xiaofeng 1; Jiang, Haichang 1; Rong, Lijian 1
通讯作者	Hu, Xiaofeng(xfhu@imr.ac.cn)
	2024-09-11
发表期刊	ACTA METALLURGICA SINICA
ISSN	0412-1961
卷号	60 期号:9 页码:1200-1212
摘要	Due to the worsening of environmental pollution and energy shortage, nuclear energy has become an increasingly important energy source, offering clean, high-energy, safe, and stable power to meet the needs of modern life and production. P91 steel is an excellent heat-resistant steel, widely used in nuclear power plants for its good mechanical properties, high thermal conductivity, and low irradiation swelling rate. However, with the emergence of lead and lead- bismuth eutectic (LBE) cooled fast reactors (LFRs), P91 steel s inferior compatibility with LBE has limited its use in LFR construction. To address this issue, 9Cr ferritic/martensitic steel with high Si content (H-Si steel) was designed in this study to develop a compatible structural material for LFR heat exchange tubes. In addition, the effects of Si on the microstructure and mechanical properties of as-cast, homogenized, tempered, and aged H- Si steel were investigated using various techniques, including OM, FESEM, TEM, EBSD, tensile, and impact tests. The results show that the increase in Si content leads to 3.9% 8 ferrite (volume fraction) in as-cast H-Si steel, which can be eliminated completely by homogenization heat treatment. Tempering produces a Si-enriched layer around M 23 C 6 due to the high Si content in the H-Si steel, which can suppress the rapid growth of M 23 C 6 and maintain a smaller size of M 23 C 6 than that of M 23 C 6 in P91 steel. Meanwhile, the Si- enriched layer can slow down the growth of M 23 C 6 and promote the nucleation and growth of the Laves phase during aging at 550 degrees C, which induces smaller M 23 C 6 and larger Laves phase in aged H-Si steel than that in aged P91. Due to the higher Si content and smaller M 23 C 6 , the tempered H-Si steel exhibits significantly higher strength than P91. After aging, the strength of H-Si steel further increases because of the precipitation of the Laves phase. Both tempered alloy steels have similar impact energy (about 210 J) and the fracture mode is ductile fracture. However, the precipitation of the Laves phase after aging decreases the impact energy of both alloy steels. The aged H-Si steel had a larger and more Laves phase, resulting in a partial cleavage area in the impact fracture surface and inducing a lower impact energy compared to H-Si steel.
关键词	Si M 23 C 6 Laves phase 8 ferrite mechanical property
DOI	10.11900/0412.1961.2022.00398
收录类别	SCI
语种	英语
WOS研究方向	Metallurgy & Metallurgical Engineering
WOS类目	Metallurgy & Metallurgical Engineering
WOS记录号	WOS:001320333900005
出版者	SCIENCE PRESS
引用统计	被引频次：2[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/191568
专题	中国科学院金属研究所
通讯作者	Hu, Xiaofeng
作者单位	1.Chinese Acad Sci, CAS Key Lab Nucl Mat & Safety Assessment, Inst Met Res, Shenyang 110016, Peoples R China 2.Univ Sci & Technol China, Sch Mat Sci & Engn, Shenyang 110016, Peoples R China
推荐引用方式 GB/T 7714	Zhang, Qiankun,Hu, Xiaofeng,Jiang, Haichang,et al. Effect of Si on Microstructure and Mechanical Properties of a 9Cr Ferritic/Martensitic Steel[J]. ACTA METALLURGICA SINICA,2024,60(9):1200-1212.
APA	Zhang, Qiankun,Hu, Xiaofeng,Jiang, Haichang,&Rong, Lijian.(2024).Effect of Si on Microstructure and Mechanical Properties of a 9Cr Ferritic/Martensitic Steel.ACTA METALLURGICA SINICA,60(9),1200-1212.
MLA	Zhang, Qiankun,et al."Effect of Si on Microstructure and Mechanical Properties of a 9Cr Ferritic/Martensitic Steel".ACTA METALLURGICA SINICA 60.9(2024):1200-1212.