0.6Ni中碳合金钢的奥氏体连续冷却转变行为

doi:10.13251/j.issn.0254-6051.2020.04.003

摘要/Abstract

摘要： 通过热模拟试验、光学和扫描电镜(SEM)观察以及维氏硬度测试,研究了0.6Ni中碳合金钢的动态和静态奥氏体连续冷却转变规律,分析了变形以及合金元素Ni对中碳合金钢奥氏体转变行为的影响。结果表明:奥氏体变形有效抑制了0.6Ni中碳合金钢连续冷却后铁素体和珠光体的形成,大幅促进了贝氏体和马氏体相变,将全马氏体临界冷速由5 ℃/s降低到3 ℃/s。试验钢在动态连续冷却条件下,冷速为3 ℃/s时,全马氏体组织显微硬度为810 HV0.1;而静态连续冷却条件下,冷速为5 ℃/s时,全马氏体组织显微硬度为689 HV0.1。奥氏体变形的再结晶细化作用可以明显细化冷却后的马氏体组织,进而提高马氏体的硬度。在奥氏体静态连续冷却条件下,中碳合金钢中0.6Ni元素的加入,抑制了铁素体和珠光体相变,大幅促进贝氏体和马氏体相变,提高了奥氏体的稳定性,将Ms点从329 ℃降低到304 ℃,马氏体临界冷速从0.5 ℃/s降低到0.3 ℃/s;相对于约0.4Mn元素的加入,0.6Ni元素的加入可以大幅抑制铁素体和珠光体相变,可以将Ms点从320 ℃降低到304 ℃,同时可以有效细化奥氏体冷却后的显微组织。

关键词: 中碳合金钢, CCT曲线, 合金元素, 显微组织, 硬度

Abstract: The dynamic and static continuous cooling transformation and effects of deformation and nickel in 0.6Ni medium carbon steel were carefully investigated by means of hot simulation tests, optical microscope and SEM observations and Vickers hardness test. Experimental results show that the ferrite and pearlite transformations are effectively suppressed while the bainite and martensite transformations are greatly promoted by the deformation in austenite region of the tested steel. Then, the critical cooling rate of full martensite is also lowered from 5 ℃/s to 3 ℃/s. The hardness of full martensite is 810 HV0.1 at the cooling rate of 3 ℃/s under the dynamic continuous cooling condition. However, the hardness of full martensite is 689 HV0.1 at the cooling rate of 5 ℃/s under the static continuous cooling condition. The improvement of martensite hardness can be attributed to the refinement of martensite due to the deformation recrystallization of austenite. The ferrite and pearlite transformations are suppressed and the bainite and martensite transformations are promoted by the addition of 0.6Ni because of the improvement of austenite stability. Then, the Ms temperature is lowered from 329 ℃ to 304 ℃ and also the critical cooling rate of martensite transformation is reduced from 0.5 ℃/s to 0.3 ℃/s. Compared with that of the addition of 0.4Mn, the ferrite and pearlite transformation is largely hindered and the Ms temperature is lowered from 320 ℃ to 304 ℃ by the addition of 0.6Ni. At the same time, the microstructure after cooling is also effectively refined.

Key words: medium carbon alloying steel, CCT curves, alloying element, microstructure, hardness

中图分类号:

TG142.1

蒋波, 胡学文, 周乐育, 王芝林, 赵海东, 刘雅政. 0.6Ni中碳合金钢的奥氏体连续冷却转变行为[J]. 金属热处理, 2020, 45(4): 10-15.

Jiang Bo, Hu Xuewen, Zhou Leyu, Wang Zhilin, Zhao Haidong, Liu Yazheng. Continuous cooling transformation behavior of austenite in 0.6Ni alloyed medium carbon steel[J]. Heat Treatment of Metals, 2020, 45(4): 10-15.

参考文献

[1]高红梅, 文超, 孙轶山. 显微组织和温度对 42CrMo4 钢力学性能的影响[J]. 材料热处理学报, 2018, 39(3): 87-92.
Gao Hongmei, Wen Chao, Sun Yishan. Effects of microstructure and temperature on mechanical properties of 42CrMo4 steel[J]. Transactions of Materials and Heat Treatment, 2018, 39(3): 87-92.
[2]刘敬平, 王翠芳, 卢杉. 42CrMo 钢半轴的断裂失效分析[J]. 热加工工艺, 2017, 46(16): 251-253.
Liu Jingping, Wang Cuifang, Lu Shan. Fracture failure analysis of 42CrMo steel half shaft[J]. Hot Working Technology, 2017, 46(16): 251-253.
[3]戴玉同, 陈洪, 钱喜根. 42CrMo 钢大型环锻件的热处理工艺改进[J]. 金属热处理, 2014, 39(1): 120-123.
Dai Yutong, Chen Hong, Qian Xigen. Heat treatment process improvement for 42CrMo steel large ring forging[J]. Heat Treatment of Metals, 2014, 39(1): 120-123.
[4]管敏超, 李振华, 左训伟, 等. 42CrMo 钢大直径长轴件的淬火冷却工艺[J]. 金属热处理, 2015, 40(1): 74-78.
Guan Minchao, Li Zhenhua, Zuo Xunwei, et al. Quenching process for 42CrMo steel large diameter and long shaft[J]. Heat Treatment of Metals, 2015, 40(1): 74-78.
[5]孙岩, 安治国, 张国涛, 等. Cr-Mo系调质钢的连续冷却转变规律[J]. 金属热处理, 2019, 44(4): 62-65.
Sun Yan, An Zhiguo, Zhang Guotao, et al. Continuous cooling transformation law of Cr-Mo quenched and tempered steel[J]. Heat Treatment of Metals, 2019, 44(4): 62-65.
[6]Jiang B, Zhou L, Wen X, et al. Heat treatment properties of 42CrMo steel for bearing ring of varisized shield tunneling machine[J]. Acta Metallurgica Sinica (English Letters), 2014, 27(3): 383-388.
[7]刘雅政, 黄斌, 蒋波, 等. 盾构机轴承用钢的开发与质量控制[J]. 钢铁, 2014, 49(5): 1-6.
Liu Yazheng, Huang Bin, Jiang Bo, et al. Development and quality control of bearing steel for tunnel shield machine[J]. Iron and Steel, 2014, 49(5): 1-6.
[8]李昭昆, 雷建中, 徐海峰, 等. 国内外轴承钢的现状与发展趋势[J]. 钢铁研究学报, 2016, 28(3): 1-12.
Li Zhaokun, Lei Jianzhong, Xu Haifeng, et al. Current status and development of bearing steel in China and abroad[J]. Journal of Iron and Steel Research, 2016, 28(3): 1-12.
[9]Zhao H, Wynne B P, Palmiere E J. Effect of austenite grain size on the bainitic ferrite morphology and grain refinement of a pipeline steel after continuous cooling[J]. Materials Characterization, 2017, 123: 128-136.
[10]Kakhki M E, Kermanpur A, Golozar M A. Numerical simulation of continuous cooling of a low alloy steel to predict microstructure and hardness[J]. Modelling and Simulation in Materials Science and Engineering, 2009, 17(4): 045007.
[11]Zhao M C, Yang K, Xiao F R, et al. Continuous cooling transformation of undeformed and deformed low carbon pipeline steels[J]. Materials Science and Engineering A, 2003, 355(1/2): 126-136.
[12]Zhang C, Cai D, Wang Y, et al. Effects of deformation and Mo, Nb, V, Ti on continuous cooling transformation in Cu-P-Cr-Ni-Mo weathering steels[J]. Materials Characterization, 2008, 59(11): 1638-1642.
[13]De Andrés C G, Capdevila C, Caballero F G, et al. Effect of molybdenum on continuous cooling transformations in two medium carbon forging steels[J]. Journal of Materials Science, 2001, 36(3): 565-571.
[14]李晓成, 郑亚风, 吴晓春. 晶粒尺寸对贝氏体钢SDP1的连续冷却转变规律的影响[J]. 材料导报, 2018, 31(6): 86-92.
Li Xiaocheng, Zheng Yafeng, Wu Xiaochun. Influence of grain size on continuous cooling transformation rules of a bainitic steel SDP1[J]. Materials Review, 2018, 31(6): 86-92.
[15]何雪松, 左鹏鹏, 吴晓春. Ni对新型压铸模具钢连续冷却转变规律的影响[J]. 材料热处理学报, 2015, 36(10): 134-140.
He Xuesong, Zuo Pengpeng, Wu Xiaochun. Effect of Ni on continuous cooling transformation characteristic of new type die-casting steels[J]. Transactions of Materials and Heat Treatment, 2015, 36(10): 134-140.
[16]Tartaglia J M, Kuelz A N, Thelander V H. The Effects of alloying elements on the continuous cooling transformation behavior of 21/4Cr-1Mo steels[J]. Journal of Materials Engineering and Performance, 2018, 27(12): 6349-6364.
[17]王纳, 张宇, 李小宝, 等. Mn和 Mo对耐候钢连续冷却转变行为和强度的影响[J]. 金属热处理, 2015, 40(3): 6-10.
Wang Na, Zhang Yu, Li Xiaobao, et al. Effects of Mn and Mo on continuous cooling transformation behavior and strength of weathering steel[J]. Heat Treatment of Metals, 2015, 40(3): 6-10.
[18]陈明毅, 杨占兵, 陈曦, 等. 一种高强无碳贝氏体非调质钢的过冷奥氏体动态连续冷却转变曲线[J]. 金属热处理, 2018, 43(11): 11-15.
Chen Mingyi, Yang Zhanbing, Chen Xi, et al. Dynamic continuous cooling transformation curves of under-cooled austenite of a kind of high strength carbide-free bainite non-quenched and tempered steel[J]. Heat Treatment of Metals, 2018, 43(11): 11-15.
[19]胡光, 史显波, 曾云鹏, 等. 铜对管线钢连续冷却转变行为的影响[J]. 金属热处理, 2019, 44(7): 106-111.
Hu Guang, Shi Xianbo, Zeng Yunpeng, et al. Effect of copper on continuous cooling transformation behavior of pipeline steels[J]. Heat Treatment of Metals, 2019, 44(7): 106-111.
[20]蒋波, 霍朝霞, 周乐育, 等. 奥氏体变形和 Mn 对 42CrMo 钢连续冷却相变组织的影响[J]. 材料热处理学报, 2014, 30(8): 119-124.
Jiang Bo, Huo Zhaoxia, Zhou Leyu, et al. Effect of austenite deformation and manganese content on microstructure of continuous cooling transformation of 42CrMo steel[J]. Transactions of Materials and Heat Treatment, 2014, 30(8): 119-124.
[21]Liu J, Yu H, Zhou T, et al. Effect of double quenching and tempering heat treatment on the microstructure and mechanical properties of a novel 5Cr steel processed by electro-slag casting[J]. Materials Science and Engineering A, 2014, 619: 212-220.
[22]Jiang B, Dong Z, Zhou L, et al. Microstructural characterization and hardening mechanism of steel for large size bearing ring under fast heating and short soaking time condition[J]. Steel Research International, 2016, 87(9): 1127-1136.
[23]Wang X, Du L, Xie H, et al. Effect of deformation on continuous cooling phase transformation behaviors of 780 MPa Nb-Ti ultra-high strength steel[J]. Steel Research International, 2011, 82(12): 1417-1424.
[24]张宇, 刘仁东, 王科强, 等. 42CrMo 钢动态CCT 曲线及组织转变[J]. 金属热处理, 2012, 37(12): 37-40.
Zhang Yu, Liu Rendong, Wang Keqiang, et al. Dynamic continuous cooling transformation curves and microstructure evolution of 42CrMo steel[J]. Heat Treatment of Metals, 2012, 37(12): 37-40.