Nb对中碳钢相变和组织细化的影响<sup>*</sup>

doi:10.3724/SP.J.1037.2013.00538

金属学报

2014, Vol. 50

Issue (4): 400-408 DOI: 10.3724/SP.J.1037.2013.00538

本期目录 | 过刊浏览

Nb对中碳钢相变和组织细化的影响^*

吴斯, 李秀程, 张娟, 尚成嘉(

)

北京科技大学材料科学与工程学院, 北京 100083

EFFECT OF Nb ON TRANSFORMATION AND MICROSTRUCTURE REFINEMENT IN MEDIUM CARBON STEEL

WU Si, LI Xiucheng, ZHANG Juan, SHANG Chengjia(

)

School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083

引用本文:

吴斯, 李秀程, 张娟, 尚成嘉. Nb对中碳钢相变和组织细化的影响^*[J]. 金属学报, 2014, 50(4): 400-408.
Si WU, Xiucheng LI, Juan ZHANG, Chengjia SHANG. EFFECT OF Nb ON TRANSFORMATION AND MICROSTRUCTURE REFINEMENT IN MEDIUM CARBON STEEL[J]. Acta Metall Sin, 2014, 50(4): 400-408.

全文: PDF(7717 KB) HTML

摘要:

针对无Nb和添加0.06%Nb的2种中碳钢, 研究了Nb对0.47%C中碳钢相变及组织细化的影响规律. 2种实验钢正火组织均为铁素体+珠光体, Nb微合金化能够有效细化中碳钢的奥氏体晶粒, 从而导致正火后组织中铁素体体积分数明显增加. 含Nb中碳钢的屈服强度相对无Nb钢提高了18% (70 MPa), 抗拉强度基本保持不变, -20 ℃冲击韧性则由7 J提高到19 J, 呈现显著提高. 此外, 由连续冷却转变(CCT)曲线发现, Nb微合金化中碳钢可在冷速≤10 ℃/s时获得较高体积分数的铁素体, 因此, 可保证工件在较大冷速范围内不出现大块珠光体或贝氏体/马氏体组织. 结合TEM观察发现, Nb元素以微小析出物Nb(C, N)的状态均匀分布在钢中. Nb(C, N)析出物能有效细化奥氏体晶粒, 并因此提高铁素体形核率, 这是Nb在中碳钢中影响相变并提高韧性的主要机制.

关键词 ：中碳钢, Nb微合金化, 组织细化, CCT曲线, 析出物

Abstract：

Medium carbon steel is widely used in structural steels because of its favorable strength, but lack of toughness is a limitation in industrial applications. Among the different strengthening mechanism, grain refinement is the only method to improve both strength and toughness simultaneously. The toughness of steels can be affected by micro-alloying elements and microstructures, for medium carbon wheel steel, the fracture toughness is proportional to the square root of ferrite fraction and inversely proportional to the cube root of prior austenitic grain size. In this work, Nb micro-alloying is used to improve mechanical properties of medium carbon steel. Microstructures and mechanical properties of Nb-bearing medium carbon steel were studied in contrast with traditional Nb-free steel. The continuous cooling transformation (CCT) curves of investigated steels were drawn by adopting dilatometry and metallographic method. The typical microstructures were observed by OM and SEM with EDS. The morphologies of precipitates were obtained by TEM. The effects of cooling rates on microstructure and hardness of the steel were studied with the above experimental methods. The results showed that the typical microstructure of medium carbon steel was ferrite and pearlite and the volume fraction of ferrite was increased from 4% to 24% by adding 0.06%Nb with refined microstructure. The yield strength of Nb-bearing steel was improved from 385 to 455 MPa and the Charpy V-notch energy at -20 ℃ was increased from 7 to 19 J in the condition of almost no reduction in tensile strength. It is because of Nb addition, which makes the transformation products of medium carbon steel be composed of ferrite and pearlite in a wider region of cooling rates (≤10 ℃/s) and a broader temperature range (530~690 ℃), with the hardness lower than 300 HV. With the calculation of Thermal-Calc software and solid solubility formula, Nb exists in medium carbon steel in the form of precipitate. The result of observation by TEM indicates the size of Nb precipitates was distributed in 20~50 nm. To sum up, the grain refining and precipitation strengthening are the main mechanism of Nb to promote the ferrite-pearlite transformation and improve toughness in medium carbon steel.

Key words： medium carbon steel Nb micro-alloying microstructure refining CCT curve precipitate

收稿日期: 2013-08-30

ZTFLH:

TG113

基金资助:* 国家重点基础研究发展计划资助项目 2010CB630801

作者简介: null

吴斯, 男, 1985年生, 博士生

	服务

	把本文推荐给朋友
	加入引用管理器
	E-mail Alert
	RSS
	作者相关文章
	吴斯
	李秀程
	张娟
	尚成嘉
44.8K

链接本文:

https://www.ams.org.cn/CN/10.3724/SP.J.1037.2013.00538 或 https://www.ams.org.cn/CN/Y2014/V50/I4/400

表1 实验中碳钢的化学成分

图1

图2

图3

图 4

图5

图6

图7

图8

图9

[1]	Zerbst U, Mädler K, Hintze H. Eng Fract Mech, 2005; 72: 163
[2]	Ekberg A, Kabo E. Wear, 2005; 258: 1288
[3]	Cui Y H, Zhang J P, Su H, Jiang B. Res Iron Steel, 2005; 114: 53
[3]	(崔银会, 张建平, 苏航, 江波. 钢铁研究, 2005; 114: 53)
[4]	Miao C L, Shang C J, Zhang G D, Subramanian S V. Mater Sci Eng, 2010; A527: 4985
[5]	Gong W M, Yang C F, Zhang Y Q. J Iron Steel Res, 2006; 18(10): 49
[5]	(龚维幂, 杨才福, 张永权. 钢铁研究学报, 2006; 18(10): 49)
[6]	Hansen S S, Krauss G, Banerji S K. Proc Int Conf on Welding Metallurgy of Structural Steels, Warrendale, PA: TMS-AIME, 1987: 155
[7]	Pickering F B, Garbarz B. Mater Sci Technol, 1989; 5: 227
[8]	Sakamoto H, Toyama K, Hirakawa K. Mater Sci Eng, 2000; A285: 288
[9]	Wu S, Li X C, Shang C J, Han J S, Wang Q D. Trans Mater Heat Treat, 2012; 33(7): 100
[9]	(吴斯, 李秀程, 尚成嘉, 韩建生, 王群娣. 材料热处理学报, 2012; 33(7): 100)
[10]	Lan Y J, Li D Z, Li Y Y. Acta Mater, 2004; 56: 1721
[11]	Li X C, Xia D X, Wang X L, Wang X M, Shang C J. Sci China Technol Sci, 2013; 56(1): 66
[12]	Fu J Y. Iron Steel, 2005; 40(8): 1
[12]	(付俊岩. 钢铁, 2005; 40(8): 1)
[13]	Tither G. Proceeding of the International Symposium Niobium 2001, Orlando: Niobium 2001 Limited, 2001: 1
[14]	GB/T 6394-2002. Metal-Methods for Estimating the Average Grain Size. Beijing: Standardization Administration of the People's Republic of China, 2002
[14]	(国标GB/T 6394-2002. 金属平均晶粒度测定法. 6394-2002. 金属平均晶粒度测定法. 北京: 国家标准化管理委员会, 2002)
[15]	Yong Q L. Secondary Phases in Steel. Beijing: Metallurgical Industry Press, 2006: 145
[15]	(雍岐龙. 钢铁材料中的第二相. 北京: 冶金工业出版社, 2006: 145)
[16]	Narita K. Kobe Steel Eng Rep, 1966; 16: 179
[17]	Zheng L, Yong Q L, Sun Z B. Acta Metall Sin, 1987; 23: 547
[17]	(郑鲁, 雍岐龙, 孙珍宝. 金属学报, 1987; 23: 547)
[18]	Chi H X, Ma D S, Liu J H, Chen Z Z, Yong Q L. Acta Metall Sin, 2010; 46: 206
[18]	(迟宏宵, 马党参, 刘建华, 陈再枝, 雍岐龙. 金属学报, 2010; 46: 206)
[19]	Gladman T. Proc Roy Soc, 1966; 294: 298
[20]	Gladman T. HSLA Steels. Warrendale, PA: TMS-AIME, 1992: 3
[21]	Gladman T. Mater Sci Technol, 1999; 15(1): 30
[22]	Lee K J, Kang K B, Lee J K, Kwon O, Chang R W. Proceedings of the International Conference in Mathematical Modelling of Hot Rolling of Steel, Hamilton, Canada: AIME, 1990: 435
[23]	Mecozzi M G, Sietsma J, Zwaag S. Acta Mater, 2006; 54: 1431
[24]	Gladman T. Recrystallization and Grain Growth of Multi-phase and Particle Containing Materials. Oskilde, Denmark: Riso National Laboratory, 1980: 183
[25]	Kop T A, Sietsma J, Zwaag S. Mater Sci Technol, 2001; 36: 1569
[26]	Wagner V, Starke P, Kerscher E, Eifler D. Int J Fatigue, 2011; 33: 69
[27]	Ahlström J, Karlsson B. Wear, 1999; 232: 1
[28]	Aglan H A, Liu Z Y, Hassan M F, Fateh M. J Mater Process Technol, 2004; 151: 268
[29]	Shang C J, Wu S, Li X C, He F, Wang X M. Chin Pat, 201210065521.6, 2012
[29]	(尚成嘉, 吴斯, 李秀程, 贺飞, 王学敏. 中国专利, 201210065521.6, 2012)

[1]	王周头, 袁清, 张庆枭, 刘升, 徐光. 冷轧中碳梯度马氏体钢的组织与力学性能[J]. 金属学报, 2023, 59(6): 821-828.
[2]	刘洁, 徐乐, 史超, 杨少朋, 何肖飞, 王毛球, 时捷. 稀土Ce对非调质钢中硫化物特征及微观组织的影响[J]. 金属学报, 2022, 58(3): 365-374.
[3]	李根, 兰鹏, 张家泉. 基于Ce变质处理的TWIP钢凝固组织细化[J]. 金属学报, 2020, 56(5): 704-714.
[4]	惠亚军, 刘锟, 吴科敏, 李秋寒, 牛涛, 武巧玲. 卷取温度对500 MPa级热冲压桥壳用钢组织与力学性能的影响[J]. 金属学报, 2020, 56(12): 1605-1616.
[5]	武慧东, 宫本吾郎, 杨志刚, 张弛, 陈浩, 古原忠. Fe-1.5(3.0)%Si-0.4%C合金贝氏体不完全转变现象及伴随的渗碳体析出[J]. 金属学报, 2018, 54(3): 367-376.
[6]	何仙灵,杨庚蔚,毛新平,余驰斌,达传李,甘晓龙. Nb对Ti-Mo微合金钢连续冷却相变规律及组织性能的影响[J]. 金属学报, 2017, 53(6): 648-656.
[7]	惠亚军,潘辉,李文远,刘锟,陈斌,崔阳. 1000 MPa级Nb-Ti微合金化超高强度钢加热制度研究[J]. 金属学报, 2017, 53(2): 129-139.
[8]	杨滨, 李鑫, 罗文东, 李宇翔. 微量添加Sn和Nb对Zr-Cu-Fe-Al块体非晶合金热稳定性和塑性的影响[J]. 金属学报, 2015, 51(4): 465-472.
[9]	徐洋, 孙明雪, 周砚磊, 刘振宇. (Nb, Ti)C在轧后卷取中的析出及对铁素体相微观力学特征的影响[J]. 金属学报, 2015, 51(1): 31-39.
[10]	张杰,蔡庆伍,武会宾,樊艳秋. 快速加热回火对690 MPa级海洋工程用钢组织和性能的影响[J]. 金属学报, 2013, 49(12): 1549-1557.
[11]	杨琨,梁永锋,叶丰,林均品. Nb微合金化Fe₁₄Si₂高硅钢温轧板织构演变规律[J]. 金属学报, 2013, 49(11): 1411-1415.
[12]	贾晓帅,左训伟,陈乃录,黄坚,唐新华,戎咏华. 经新型Q－P－T工艺处理后Q235钢的组织与性能[J]. 金属学报, 2013, 49(1): 35-42.
[13]	聂文金尚成嘉吴圣杰施培建程俊杰张晓兵. Nb对奥氏体热变形后等温回复的影响[J]. 金属学报, 2012, 48(7): 775-781.
[14]	王斌,刘振宇,周晓光,王国栋. 轧后冷却路径对中碳钢扩孔性能的影响[J]. 金属学报, 2012, 48(4): 435-440.
[15]	彭云王爱华肖红军田志凌. Cu对690 MPa级HSLA钢熔敷金属组织形成和细化的作用[J]. 金属学报, 2012, 48(11): 1281-1289.

Viewed

Full text

Abstract

Cited

Shared

Discussed