Effect of Ce content on inclusions and as-cast microstructure and hardness of S355NL low alloy steel

doi:10.13251/j.issn.0254-6051.2024.12.021

Abstract

Abstract: Effects of adding different contents high-purity rare earth Ce element on the inclusions, as-cast microstructure and hardness of high-purity S355NL low alloy steel were investigated. The types, sizes and shapes of inclusions, as well as the as-cast microstructure and hardness were analyzed and evaluated by using scanning electron microscopy, optical microscopy, and Vickers hardness testing. The results indicate that with the Ce addition ranging from 0.0011% to 0.0049%, the irregularly shaped large Al₂O₃ and MnS inclusions in the S355NL low alloy steel are modified into fine spherical rare earth inclusions. When Ce is added at levels between 0.0011% and 0.0049%, it initially reacts with O and S to form small spherical rare earth oxysulfides. However, with the increase of Ce content, excess Ce can react with As and P, leading to larger irregular rare earth inclusions. Additionally, the incorporation of Ce refines the dendritic structure of the S355NL low alloy steel and enhances its hardness. Considering both the inclusion modification and hardness optimization, the optimal range for Ce addition in the S355NL low alloy steel is determined to be 0.0011% to 0.0049%.

Key words: S355NL low alloy steel, rare earth Ce, inclusions, as-cast microstructure, hardness

CLC Number:

TG142.7

Yang Jiandong, Xie Bijun, Xu Bin, Sun Mingyue, Li Dianzhong. Effect of Ce content on inclusions and as-cast microstructure and hardness of S355NL low alloy steel[J]. Heat Treatment of Metals, 2024, 49(12): 122-127.

References

[1]Zhao J, Kim W Y, Lee H J. Effect of tungsten addition on the mechanical properties and corrosion resistance of S355NL forging steel[J]. Metals and Materials International, 2012, 18(2): 217-223.
[2]戈文英. 风电塔筒法兰用S355NL钢的低温冲击韧性[J]. 特殊钢, 2015, 36(5): 47-50.
Ge Wenying . Low temperature impact toughness of steel S355NL for wind power tower flange[J]. Special Steel, 2015, 36(5): 47-50.
[3]潘中德, 郭甲男, 胡其龙. 正火温度轧制和正火处理的S355NL钢板的力学性能和显微组织[J]. 上海金属, 2022, 44(2): 61-64, 71.
Pan Zhongde, Guo Jianan, Hu Qilong. Mechanical and microstructure of S355NL steel plate rolled at normalized temperature and normalized.[J]. Shanghai Metals, 2022, 44(2): 61-64, 71.
[4]陈一满, 卢爱凤. S355NL钢低温冲击韧度不合格原因分析[J]. 理化检验(物理分册), 2017, 53(1): 73-76.
Chen Yiman, Lu Aifeng. Cause analysis of low-temperature impact toughness disqualification of S355NL steel[J]. Physical Testing and Chemical Analysis (Part A: Physical Testing), 2017, 53(1): 73-76.
[5]Li D Z, Wang P, Chen X Q, et al. Low-oxygen rare earth steels[J]. Nature Materials, 2022, 21(10): 1137-1143.
[6]Wang L, Lin Q, Yue L, et al. Study of application of rare earth elements in advanced low alloy steels[J]. Journal of Alloys and Compounds, 2007, 451(1): 534-537.
[7]安玉乾, 王林珠, 黎玉唐, 等. 稀土铈对夹杂物特征的影响[J]. 宽厚板, 2020, 26(2): 11-17.
An Yuqian, Wang Linzhu, Li Yutang, et al. Effects of rare earth cerium on the characteristics of inclusions[J]. Wide and Heavy Plate, 2020, 26(2): 11-17.
[8]陈霞文, 王天祥, 李春宏. 混合稀土对 Al-Si-Cu 系合金铸造组织与硬度的影响[J]. 南京理工大学学报, 1997(2): 65-68, 88.
Chen Xiawen, Wang Tianxiang, Li Chunhong. Influence of mischmetal to cast structure and hardness of Al-Si-Cu system alloy[J]. Journal of Nanjing University of Science and Technology, 1997(2): 65-68, 88.
[9]武悦, 马迅, 王鹏, 等. 稀土在钢中作用的研究进展[J]. 材料热处理学报, 2023, 44(2): 1-12.
Wu Yue, Ma Xun, Wang Peng, et al. Research progress of function of rare earths in steel[J]. Transactions of Materials and Heat Treatment, 2023, 44(2): 1-12.
[10]Yang C, Luan Y, Li D, et al. Effects of rare earth elements on inclusions and impact toughness of high-carbon chromium bearing steel[J]. Journal of Materials Science Technology, 2019, 35(7): 1298-1308.
[11]韩杰, 王毅, 刘成宝, 等. 稀土对GCr15轴承钢夹杂物的变质行为分析[J]. 连铸, 2023(2): 70-77.
Han Jie, Wang Yi, Liu Chengbao, et al. Analysis on modification behavior of rare earth to inclusions in GCr15 bearing steel[J]. Continuous Casting, 2023(2): 70-77.
[12]杨超云, 栾义坤, 李殿中, 等. 稀土元素对高洁净度轴承钢中夹杂物的影响研究[J]. 炼钢, 2016, 32(4): 54-59, 72.
Yang Chaoyun, Luan Yikun, Li Dianzhong, et al. Effect of RE on inclusions in highly clean bearing steel[J]. Steelmaking, 2016, 32(4): 54-59, 72.
[13]汪艳亮, 王云, 谢小豪, 等. 稀土硬质合金研究进展[J]. 有色金属科学与工程, 2019, 10(5): 106-112.
Wang Yanliang, Wang Yun, Xie Xiaohao, et al. Research progress on rare earth cemented carbide[J]. Nonferrous Metals Science and Engineering, 2019, 10(5):106-112.
[14]Zhang S, Yu Y, Wang S, et al. Effects of cerium addition on solidification structure and mechanical properties of 434 ferritic stainless steel[J]. Journal of Rare Earths, 2017, 35(5): 518-524.
[15]Cheng S, Guanghong F, Jianguo Z, et al. The effect of rare earth cerium on microstructure and properties of low alloy wear-resistant steel[J]. Metals, 2022, 12(8): 1358-1358.
[16]盛达, 杨守峰, 臧晓云, 等. 稀土对白口铸铁组织和性能的影响[J]. 稀土, 1994(6): 39-43.