| delta-ferrite transformation mechanism and its effect on mechanical properties of 316H weld metal | |
| Zhao, Langlang1,2,3; Wei, Shitong1; Wu, Dong3; Gao, Dianbao4; Lu, Shanping3 | |
| Corresponding Author | Lu, Shanping(shplu@imr.ac.cn) |
| 2020-11-15 | |
| Source Publication | JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
 |
| ISSN | 1005-0302 |
| Volume | 57Pages:33-42 |
| Abstract | The microstructure evolution and mechanical properties of the 316H stainless steel weld metals with different C contents were studied at the aging temperature of 550 degrees C for different aging holding time. The transformation behavior of delta-ferrite and precipitation mechanisms of M23C6 and sigma phase in the as -aged weld metal were investigated. The results indicated that for the as-welded weld metal, with increasing C content, the yield and tensile strengths increased, while the elongation decreased owing to the increase of C solid solution strengthening effect. Moreover, both the high delta-ferrite content in low C weld metal and the precipitated M23C6 carbide in high C weld metal deteriorated the impact energy obviously. During the aging process, the rapid precipitation of M23C6 carbide occurred in 8 -ferrite firstly owing to the high diffusion rate of C. Once the carbon is depleted by precipitation of M23C6, the slow formation of Cr phase occurred through eutectoid transformation (delta -> sigma + gamma) depending on the diffusion of Cr and Mo. Moreover, increasing C content promoted the formation of M23C6 carbides and inhibited the formation of sigma phase. Therefore, increasing C content accelerated the transformation of 8 -ferrite in weld metal during aging process. Furthermore, after a long enough aging time, a transformation from M23C6 to sigma occurred. The variations of mechanical properties with aging conditions depended to a large extent on the microstructures at different aging conditions. For the low C weld metal aged at 550 degrees C, with the increase of the aging time, fine M23C6 first precipitated, then coarsened, after that Cr phase formed, which caused that the yield and tensile strengths first increased, then decreased, and finally increased slightly again. For the medium C weld metal, as the aging time increased, first the depletion of the solid solution C as a result the M23C6 precipitation deteriorated the strength, and then the formation of Cr phase improved the strength. For the high C weld metal, with the increase of the aging time, the depletion of the solid solution C and the coarsening of the M23C6 precipitates deteriorated the strength. Furthermore, with increasing aging time, both the precipitation and coarsening of M23C6 and increasing sigma phase content deteriorated the elongation and impact energy. (C) 2020 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology. |
| Keyword | 316H weld metal Aging treatment 8-ferrite M23C6 sigma phase Mechanical property |
| Funding Organization | Opening Foundation of Key Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Academy of Sciences ; China Institute of Atomic Energy |
| DOI | 10.1016/j.jmst.2020.02.085 |
| Indexed By | SCI |
| Language | 英语 |
| Funding Project | Opening Foundation of Key Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Academy of Sciences[2019NMSAKF04] ; China Institute of Atomic Energy[2016-DGB-I-KYSC-0024] |
| WOS Research Area | Materials Science ; Metallurgy & Metallurgical Engineering |
| WOS Subject | Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering |
| WOS ID | WOS:000572537200004 |
| Publisher | JOURNAL MATER SCI TECHNOL |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.imr.ac.cn/handle/321006/140647 |
| Collection | 中国科学院金属研究所 |
| Corresponding Author | Lu, Shanping |
| Affiliation | 1.Chinese Acad Sci, Inst Met Res, Key Lab Nucl Mat & Safety Assessment, Shenyang 110016, Peoples R China 2.Univ Sci & Technol China, Sch Mat Sci & Engn, Shenyang 110016, Peoples R China 3.Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Peoples R China 4.China First Heavy Ind, Nucl Power & Petro Chem Business Grp, Dalian 116113, Peoples R China |
| Recommended Citation GB/T 7714 | Zhao, Langlang,Wei, Shitong,Wu, Dong,et al. delta-ferrite transformation mechanism and its effect on mechanical properties of 316H weld metal[J]. JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY,2020,57:33-42. |
| APA | Zhao, Langlang,Wei, Shitong,Wu, Dong,Gao, Dianbao,&Lu, Shanping.(2020).delta-ferrite transformation mechanism and its effect on mechanical properties of 316H weld metal.JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY,57,33-42. |
| MLA | Zhao, Langlang,et al."delta-ferrite transformation mechanism and its effect on mechanical properties of 316H weld metal".JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY 57(2020):33-42. |
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