Effect of Nb element on grain coarsening of automobile carburized gear steel 20CrMnTi during heat treatment

doi:10.13251/j.issn.0254-6051.2024.01.017

Abstract

Abstract: Grain growth and precipitation particle distribution of two kinds of industrial carburized gear steels under the same pseudo-carburizing process were analyzed. Besides, the role of Nb element in automobile gear carburized steel was clarified. The results show that the addition of 0.02%wt Nb reduces the addition of 0.02%wt Mo and 0.02%wt Ti, and the austenite grain size of the Nb-Ti-Mo steel is slightly smaller than that of the Ti-Mo steel after carburizing at 960 ℃ for 4 h. Furthermore, the degree of mixed crystal is reduced in the Nb-Ti-Mo steel. In addition, with the addition of the Nb, the volume fraction of precipitated particles in Nb-Ti-Mo steel after carburizing at 960 ℃ for 4 h is slightly less than that of the Ti-Mo steel, but the average size of precipitated particles is smaller than that of the Ti-Mo steel, providing better pinning effect and grain refinement. The addition of the mass fraction of 0.02wt%Nb improves the thermal stability of precipitated particles and provides better precipitation strengthening effect, and the contribution of precipitation strengthening is 87.54 MPa.

Key words: Nb, pseudo-carburizing, austenite, grain size, precipitation

CLC Number:

TG142.1

Zheng Daoyou, Zhang Rui, Tang En. Effect of Nb element on grain coarsening of automobile carburized gear steel 20CrMnTi during heat treatment[J]. Heat Treatment of Metals, 2024, 49(1): 113-118.

References

[1]吴园园, 石丽丽, 张继明. 齿轮钢中渗氮层深度及含量的测定方法[J]. 冶金分析, 2022, 42(10): 38-42.
Wu Yuanyuan, Shi Lili, Zhang Jiming. Determination method of depth and content of nitriding layer in gear steel[J]. Metallurgical Analysis, 2022, 42(10): 38-42.
[2]范斌, 刘利, 张时雨, 等. 齿轮钢20CrMnTiH淬透性/宏观偏析控制[J]. 连铸, 2023(1): 47-54.
Fan Bin. Liu Li, Zhang Shiyu, et al. Gear steel 20CrMnTiH hardenability/macro segregation control[J]. Continuous Casting, 2023(1): 47-54.
[3]张伟, 谌康, 李慧超, 等. Nb对20CrMo齿轮钢渗碳层深度和硬度的影响[J]. 金属热处理, 2021, 46(10): 31-34.
Zhang Wei, Shen Kang, Li Huichao, et al. Effect of Nb on carburizing depth and hardness of 20CrMo gear steel[J]. Heat Treatment of Metals, 2021, 46(10): 31-34.
[4]柳洋波, 崔京玉, 佟倩, 等. 铌对20CrMnTi钢渗碳过程中晶粒粗化行为的影响[J]. 材料热处理学报, 2015, 36(1): 124-131.
Liu Yangbo, Cui Jingyu, Tong Qian, et al. Effect of niobium on grain coarsening behavior of 20CrMnTi steel during carburizing[J]. Transactions of Materials and Heat Treatment, 2015, 36(1): 124-131.
[5]乔晓阳, 裴小芳, 崔冕, 等. 易切削齿轮钢22CrMoHS的开发[J]. 特殊钢, 2020, 41(3): 32-34.
Qiao Xiaoyang, Pei Xiaofang, Cui Mian, et al. Development of free cutting 22CrMoHS gear steel[J]. Special Steel, 2020, 41(3): 32-34.
[6]彭朝晖, 赵燕, 黄云奇. 齿轮用渗碳钢20CrMnTi渗碳畸变的研究[J]. 热加工工艺, 2008, 37(12): 77-81.
Peng Chaohui, Zhao Yan, Huang Yunqi. Study on carburizing distortion of 20CrMnTi case-hardened steel[J]. Hot Working Technology, 2008, 37(12): 77-81.
[7]王昊杰, 郝浩腾, 王昭东, 等. 渗碳工艺参数对常见渗碳钢晶粒粗化行为的影响[J]. 材料热处理学报, 2017, 38(3): 177-185.
Wang Haojie, Hao haoteng, Wang Zhaodong, et al. Effect of carburizing process parameters on austenitic grain coarsening behavior of common carburizing steel[J]. Transactions of Materials and Heat Treatment, 2017, 38(3): 177-185.
[8]戴新财. 渗碳齿轮钢晶粒粗化与渗碳工艺的关系推导[J]. 铸造技术, 2018, 39(7): 1586-1590.
Dai Xincai. Derivation of relationship between grain coarsening and carburizing process of gear steel[J]. Foundry Technology, 2018, 39(7): 1586-1590.

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