Journal of Jilin University(Engineering and Technology Edition) ›› 2020, Vol. 50 ›› Issue (2): 520-525.doi: 10.13229/j.cnki.jdxbgxb20190012

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Effect of isothermal heat treatment temperature on microstructure and mechanical properties of super bainite

Wen-cui XIU1,2(),Hua WU1(),Ying HAN1,Yun-xu LIU1   

  1. 1.Key Laboratory of Advanced Structural Materials of Ministry of Education，Changchun University of Technology，Changchun 130012, China
    2.School of Mechanical and Civil Engineering，Jilin Agricultural Science and Technology University, Jilin 132101, China
  • Received:2019-01-04 Online:2020-03-01 Published:2020-03-08
  • Contact: Hua WU E-mail:xiuwencui@jlnku.edu.cn;wuhua@ccut.edu.cn

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Abstract:

In order to study the super-bainite structure transformation of 70Si2Mn2CrMo steel after isothermal heat treatment at different temperatures, the precipitation of carbide and its mechanical properties were studied. The temperature and type of carbide precipitation were determined by the analysis of the microstructure and mechanical properties of the sample. It is shown that the precipitation of carbide reduces the carbon content in the overcooling austenite, resulting in low stability of the steel and the volume fraction of retained austenite in super-bainite is reduced. Compared with the sample of no carbide precipitation at 220 °C isothermal heat treatment, the tensile strength of the sample steel decreased by 11%, the strong plastic product decreased by 16%, and the fatigue cycle fracture times decreased by 55%, at 245 ° C isothermal heat treatment.

Key words: metal material, super-bainite, carbide precipitation, isothermal heat treatment temperature, mechanical property

CLC Number: 

  • TG142.1

Fig.1

Diagram of heat treatment process of experimental steel"

Table 1

Technical parameters of heat treatment of steel for test"

实验号温度TA/℃，时间/h温度T/℃，时间/h
1910，1195，48
2910，1220，48
3910，1245，48
4910，1350，48

Fig.2

Microstructures of experimental steel isothermal treated at different temperatures"

Table 2

Hardness value of experimental steel isothermal treated at different temperatures"

等温温度/℃硬度值/HRC
35043
24551
22054
19556

Fig.3

TEM characterization of microstructures in experimental steel isothermal treated at different temperatures"

Fig.4

XRD diffraction patterns of experimental steel isothermal treated at different temperatures"

Table 3

AR content and carbon concentration in microstructures of specimens isothermal heat treated at different temperatures"

等温热处理温度/℃残余奥氏体质量分数/%残余奥氏体中C质量分数/%
2457.730 00.878 7
2208.416 91.020 4
1955.079 31.090 9

Fig.5

Tensile stress-strain curves of specimens after isothermal heat treatment at 220 ℃ and 245 ℃"

Table 4

Tensile and fatigue test data of specimens after isothermal heat treatment at 220 ℃ and 245 ℃ respectively"

等温处理温度/℃抗拉强度/MPa伸长率/%强塑积/(MPa·%)疲劳断裂/103次
2202 3477.6417 931184
2452 0827.2415 07483

Fig.6

Fatigue fracture morphology of the experimental steel isothermal treated at different temperatures"

1 Caballero F G, Bhadeshia H K D H. Very strong bainite[J]. Current Opinion in Solid State & Materials Science, 2004, 8(3): 251-257.
2 Hase K, Garcia-Mateo C, Bhadeshia H K D H. Bimodal size-distribution of bainite plates[J]. Materials Science & Engineering A, 2006, 438-440: 145-148.
3 Luzginova N V, Zhao L, Sietsma J. Bainite formation kinetics in high carbon alloyed steel[J]. Materials Science & Engineering A, 2008, 481: 766-769.
4 Han Y, Wu H, Liu C, et al. Microstructures and mechanical characteristics of a medium carbon super-bainitic steel after isothermal transformation[J]. Journal of Materials Engineering & Performance, 2014, 23(12): 4230-4236.
5 Podder A S, Bhadeshia H K D H. Thermal stability of austenite retained in bainitic steels[J]. Materials Science & Engineering: A, 2010, 527(7/8): 2121-2128.
6 Wu H, Liu C, Zhao Z B, et al. Design of air-cooled bainitic microalloyed steel for a heavy truck front axle beam[J]. Materials and Design, 2006, 27(8): 651-656.
7 Soliman M, Mostafa H, El-Sabbagh A S, et al. Low temperature bainite in steel with 0.26 wt% C[J]. Materials Science & Engineering: A, 2010, 527(29/30): 7706-7713.
8 吴化. 低合金高强度高塑性复相钢材的成分设计[D]. 上海： 东华大学材料科学与工程学院, 2007.
Wu Hua. Composition design of low alloy high strength and plasticity complex phases steels[D]. Shanghai: College of Materials Science and Engineering, Donghua University, 2007.
9 陈连生, 张健杨, 田亚强, 等. 预先Mn配分处理对Q&P钢中C配分及残余奥氏体的影响[J]. 金属学报, 2015, 51(5): 527-536.
Chen Lian-sheng, Zhang Jian-yang, Tian Ya-qiang, et al. Effect of Mn pre-partitioning on C partitioning and retained qustenite of Q＆P steels[J]. Acta Metallurgica Sinice, 2015, 51(5): 527-536.
10 Misra A, Sharma S, Sangal S, et al. Critical isothermal temperature and optimum mechanical behaviour of high Si-containing bainitic steels[J]. Materials Science & Engineering: A, 2012, 558: 725-729.
11 康沫狂, 朱明, 陈大明, 等. 硅合金钢淬火组织中残留奥氏体的力学稳定性与力学性能[J]. 金属热处理, 2005, 30(1): 14-19.
Kang Mo-kuang, Zhu Ming, Chen Da-ming, et al. Mechanical property and mechanical stability of retained austenite in quenching microstructure of an alloy steel containing Si[J]. Heat Treatment of Metals, 2005, 30(1): 14-19.
12 Sourmail T, Smanio V. Low temperature kinetics of bainite formation in high carbon steels[J]. Acta Materialia, 2013, 61(7): 2639-2648.
13 刘宗昌, 王海燕, 王玉峰, 等. 贝氏体碳化物的形貌及形成机制[J]. 材料热处理学报, 2008, 29(1): 32-37, 46.
Liu Zong-chang, Wang Hai-yan,Wang Yu-feng, et al. Morphology and formation mechanism of bainitic carbide[J]. Transactions of Materials and Heat Treatment, 2008, 29(1): 32-37, 46.
14 蔡珣. 材料科学与工程基础［M］. 上海: 上海交通大学出版社, 2010.
15 Bhadeshia H K D H. High performance bainitic steels[J]. Materials Science Forum, 2005, 500/501: 63-74.
16 范雄. 金属X射线学[M]. 北京： 机械工业出版社, 1981.
17 吴万国, 阮玉忠, 黄清明. 残余奥氏体定量分析的特殊方法[J]. 福州大学学报： 自然科学版, 2002, 30(3): 385-386.
Wu Wan-guo, Ruan Yu-zhong, Huang Qing-ming. A special method on quantitative analysis of remnant austenite[J]. Journal of Fuzhou University (Natural Science Edition), 2002, 30(3): 385-386.
18 Mandal D, Ghosh M, Pal J, et al. Effect of austempering treatment on microstructure and mechanical properties of high-Si steel[J]. Journal of Materials Science, 2009, 44(4): 1069-1075
19 Xiu W C, Han Y, Liu C, et al. Cyclic stress induced phase transformation in super-bainitic microstructure[J]. Chinese Physics B, 2017, 26(3): 545-549.
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