Effect of normalizing process on microstructure and properties of 420 MPa grade steel plate for offshore wind power

doi:10.13251/j.issn.0254-6051.2021.10.019

Abstract

Abstract: Effect of different heat treatment processes, which are normalizing, strengthening normalizing, normalizing+400 ℃ tempering, on the microstructure and properties of 420 MPa steel plate for offshore wind power was studied by means of scanning electron microscope, laser confocal microscope, room temperature tensile test, low temperature impact test and other experimental methods. The results show that after normalization, the average grain size of the steel is refined from 8 μm to 6 μm compared with that as-rolled, the band microstructure is improved, the strength and low-temperature impact property are improved as the impact absorbed energy at －50 ℃ reaching to 120 J and the yield strength increasing to 442 MPa. After normalizing+400 ℃ tempering, the average grain size is 7 μm, the low-temperature impact property of the steel is greatly improved (the impact absorbed energy at -50 ℃ can reach 194 J), but the yield strength reduces to 422 MPa. After strengthening normalization and compared with that of normalizing, the microstructure is composed of ferrite+pearlite+a small amount of bainite, the average grain size is refined to 5.6 μm, the yield strength is increased to 460 MPa, the elongation after fracture and the low-temperature impact absorbed energy are somewhat reduced but can meet the EN10025 performance standard and achieve the best match of strength and toughness. It is proved that the strengthening normalization is the best heat treatment process for the production of 420 MPa grade offshore wind power steel.

Key words: normalizing, band microstructure, ferrite, steel plate for offshore wind power, mechanical properties

CLC Number:

TG161

Yuan Rui, Pan Zhongde, Wu Huibin. Effect of normalizing process on microstructure and properties of 420 MPa grade steel plate for offshore wind power[J]. Heat Treatment of Metals, 2021, 46(10): 112-116.

References

[1]孙一琳. 全球海上风电市场现状与展望[J]. 风能, 2020(9): 40-43.
[2]洪海云, 田小娇. 风电塔筒行业环境分析[J]. 中国电力企业管理, 2019(16): 84-85.
[3]王建华. 钢的常化(正火)处理工艺与应用[J]. 山东冶金, 1997, 19(1): 16-18.
Wang Jianhua. The technology and utilization of normalizing treatment of steel[J]. Shandong Metallurgy, 1997, 19(1): 16-18.
[4]周双双. 高强度低温用结构钢高温变形行为及热处理工艺研究[D]. 南京: 南京航空航天大学, 2017.
Zhou Shuangshuang. Research on the hot deformation behavior and heat treatment process of high strength cryogenic structural steel[D]. Nanjing: Nanjing University of Aeronautics and Astronautics, 2017.
[5]宋斌, 金恒阁, 王长生. 低温钢国内发展状况[J]. 黑龙江冶金, 2009, 29 (1): 51-52.
Song Bin, Jin Hengge, Wang Changsheng. Development of low-temperature steel in China[J]. Heilongjiang Metallurgy, 2009, 29 (1): 51-52.
[6]王璐. 铌和热处理工艺对低温钢组织和性能的影响[D]. 郑州: 郑州大学, 2011.
Wang Lu. Effect of niobium and heat treatments on microstructure and mechanical properties of cryogenic steels[D]. Zhengzhou: Zhengzhou University, 2011.
[7]石磊. 低合金高强钢相变行为及两相区热处理工艺的研究[D]. 天津: 天津大学, 2014.
Shi Lei. Research on phase transformation behavior and intercritical heat treatment of high strength low alloy steel[D]. Tianjin: Tianjin University, 2014.
[8]Zhang Y C, Meng Z S, Meng Y, et al. Effect of Nb content on the hot deformation behavior of S460ML steel[J]. Acta Metallurgica Sinica(English Letters), 2019, 32(4): 526-534.
[9]Verhoeven J D. A review of microsegregation induced banding phenomena in steels[J]. Journal of Materials Engineering and Performance, 2000, 9 (3): 286-296.
[10]冯锐. 铁素体/珠光体型钢板内部质量及其影响因素研究[D]. 济南: 山东大学, 2013.
Feng Rui. Research on internal quality and its influencing factors of ferrite/pearlite steel plate[D]. Jinan: Shandong University, 2013.
[11]Choi H J, Schwartz L H. Fatigue crack propagation in intercritically tempered Fe-9Ni-0.1C and Fe-4Mn-0.15C[J]. Metallurgical and Materials Transactions A, 1983, 14(5): 1089-1099.
[12]赵培林, 刘超, 吴会亮, 等. 正火温度对海工用355 MPa级厚规格型钢组织及低温韧性的影响[J]. 金属热处理, 2021, 46(6): 102-106.
Zhao Peilin, Liu Chao, Wu Huiliang, et al. Effect of normalizing temperature on microstructure and low temperature toughness of 355 MPa heavy section steel for marine engineering[J]. Heat Treatment of Metals, 2021, 46(6): 102-106.
[13]郑东升, 刘丹, 罗登, 等. 回火温度对工程机械用超高强钢组织及回火脆性的影响[J]. 金属热处理, 2020, 45(12): 82-86.
Zheng Dongsheng, Liu Dan, Luo Deng, et al. Effect of tempering temperature on microstructure and tempering embrittlement of ultra-high strength steel for construction machinery[J]. Heat Treatment of Metals, 2020, 45(12): 82-86.
[14]李沛海, 高鹏宇, 邓杰, 等. 兆瓦级风电后机架用Q345C/D结构钢低温冲击性能研究[J]. 热加工工艺, 2020, 49(23): 129-133.
Li Peihai, Gao Pengyu, Deng Jie, et al. Research on low temperature impact properties of Q345C/D steels for rear frame of megawatt wind turbine[J]. Hot Working Technology, 2020, 49(23): 129-133.

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