700 MPa級別熱軋高強鋼氧化鐵皮結構轉變規律

曹光明; 劉怡私; 高欣宇; 李光輝; 王皓; 劉振宇

doi:10.13374/j.issn2095-9389.2019.04.24.001

700 MPa級別熱軋高強鋼氧化鐵皮結構轉變規律

doi: 10.13374/j.issn2095-9389.2019.04.24.001

1.
東北大學軋制技術及連軋自動化國家重點實驗室，沈陽 110819
2.
華菱漣源鋼鐵有限公司，婁底 417000

基金項目: 國家重點研發計劃資助項目(2017YFB0305002)；國家自然科學基金聯合基金資助項目(U1660117)；中央高校基本科研業務費資助項目(N180704008)

詳細信息

通訊作者:
E-mail：caogm@ral.neu.edu.cn

中圖分類號: TG335.1
計量
- 文章訪問數: 1153
- HTML全文瀏覽量: 870
- PDF下載量: 61
- 被引次數: 0
出版歷程
- 收稿日期: 2019-04-24
- 刊出日期: 2019-12-01

Structural transformation of oxide scale of 700-MPa grade hot rolled high strength steel

1.
The State Key Laboratory of Rolling and Automation,Northeastern University, Shenyang 110819, China
2.
VALIN LYsteel Co., Ltd, Loudi 417000, China

More Information

Corresponding author: E-mail: caogm@ral.neu.edu.cn

摘要

摘要: 選取700 L作為試驗用典型鋼種，利用高溫同步熱分析儀（TGA）研究了熱軋過程中不同卷取溫度和冷卻速率條件對氧化鐵皮結構轉變的影響規律。實驗結果表明，450～500 ℃為700 L共析轉變的“鼻溫”區間，此時共析轉變的孕育期最短，容易發生共析轉變，生成大量的共析組織（Fe+Fe₃O₄）。相較于其他成分鋼種的氧化鐵皮共析組織轉變規律，700 L中添加的Mn、Nb、Ti元素會使晶粒細化，進而使參與反應的離子的擴散通道增加，并最終使共析轉變速率發生一定的延遲，共析“C”曲線整體出現向左偏移。
- 高強鋼 /
- 氧化鐵皮 /
- 結構轉變 /
- 共析“C”曲線 /
- Mn元素
Abstract: Due to exposure to air during rolling processes, a layer of oxide scale always coats the surface of the hot-rolled steel plates. During the subsequent cooling processes, the FeO in the oxide scale undergoes a eutectic reaction. The formation of a lamellar structure (Fe+Fe₃O₄) during this reaction is influenced by different cooling methods. The addition of alloying elements, however, also affects the eutectic reaction. The final oxide scale, hence, varieswith different compositions. For 700-MPa grade high strength steels, poor control of iron oxide scale is detrimental to the surface quality; such surface defects as iron oxide scale shedding, surface red rust, pit, are incurred. These defects, however, affect the overall performance of the steel. Consequently, the improvement of the surface quality of hot-rolled steel by controlling the iron oxide scale, without compromising the mechanical properties, has attracted the interest of many researchers. In this paper, the effect of cooling temperature and cooling rate on the structural transformation of tertiary oxide scale during hot-rolling was studied. A sample of 700 L steel grade was used. The study was carried out by the thermogravimetric analysis (TGA). The results show a "nose temperature" range of 450?500 ℃ for the 700 L eutectoid transformation. The FeO shows the shortest incubation period of eutectoid transformation, hence, is prone to eutectoid transformation, forminga large number of eutectoid phase (Fe+Fe₃O₄). Addition of alloying elements such as manganese (Mg), niobium (Nb), and titanium (Ti) to the 700 L steel lead to grain refinement in the steel. It also increases the amount of diffusion channel of ions that participate in the eutectoid phase transformation. Consequently, the eutectoid transformation is delayed, and the eutectoid " C” curve shifts to the left. This is comparableto the eutectoid transformation rule of oxide scale on the surface of other steel grades.
- high strength steel /
- oxide scale /
- structural transformation /
- eutectoid "C" curve /
- Mn element

HTML全文

圖 1 試驗用鋼的氧化鐵皮結構

Figure 1. Oxide scale structure of the tested steel

下載: 全尺寸圖片幻燈片

圖 2 0.5 ℃·min^?1冷速條件下不同卷取溫度得到的氧化鐵皮結構. (a) 650 ℃；(b) 600 ℃；(c) 550 ℃；(d) 500 ℃；(e) 450 ℃；(f) 400 ℃

Figure 2. Structure of oxide scale at different coiling temperatures at a cooling rate of 0.5 ℃·min^?1: (a) 650 ℃; (b) 600 ℃; (c) 550 ℃; (d) 500 ℃; (e) 450 ℃; (f) 400 ℃

下載: 全尺寸圖片幻燈片

圖 5 20 ℃·min^?1冷速條件下不同卷取溫度得到的氧化鐵皮結構. (a) 650 ℃；(b) 600 ℃；(c) 550 ℃；(d) 500 ℃；(e) 450 ℃；(f) 400 ℃

Figure 5. Structure of oxide scale at different coiling temperatures at a cooling rate of 20 ℃·min^?1: (a) 650 ℃; (b) 600 ℃; (c) 550 ℃; (d) 500 ℃; (e) 450 ℃; (f) 400 ℃

下載: 全尺寸圖片幻燈片

圖 3 1 ℃·min^?1冷速條件下不同卷取溫度得到的氧化鐵皮結構. (a) 650 ℃；(b) 600 ℃；(c) 550 ℃；(d) 500 ℃；(e) 450 ℃；(f) 400 ℃

Figure 3. Structure of oxide scale at different coiling temperatures at a cooling rate of 1 ℃·min^?1: (a) 650 ℃; (b) 600 ℃; (c) 550 ℃; (d) 500 ℃; (e) 450 ℃; (f) 400 ℃

下載: 全尺寸圖片幻燈片

圖 4 5 ℃·min^?1冷速條件下不同卷取溫度得到的氧化鐵皮結構. (a) 650 ℃；(b) 600 ℃；(c) 550 ℃；(d) 500 ℃；(e) 450 ℃；(f)400 ℃

Figure 4. Structure of oxide scale at different coiling temperatures at a cooling rate of 5 ℃·min^?1: (a) 650 ℃; (b) 600 ℃; (c) 550 ℃; (d) 500 ℃; (e) 450 ℃; (f) 400 ℃

下載: 全尺寸圖片幻燈片

圖 6 氧化鐵皮組織結構轉變曲線

Figure 6. Structural transformation curve of oxide scale

下載: 全尺寸圖片幻燈片

圖 7 Fe?O相圖

Figure 7. Fe?O phase diagram

下載: 全尺寸圖片幻燈片

圖 8 Fe_1?xO層組織結構轉變機制示意圖. (a) 鋼氧化后氧化鐵皮的結構；(b)先共析Fe₃O₄的生成；(c)共析組織的生成

Figure 8. Schematic diagram of transformation mechanism of Fe_1?xO layer: (a) structure of oxide scale after oxidation of steel; (b) generation of pre-eutectoid Fe₃O₄; (c) generation of eutectoid structure

下載: 全尺寸圖片幻燈片

圖 9 氧化鐵皮組織結構轉變曲線

Figure 9. Structural transformation curves of oxide scale

下載: 全尺寸圖片幻燈片

圖 10 FeO?MnO相圖

Figure 10. FeO?MnO phase diagram

下載: 全尺寸圖片幻燈片

圖 11 加入Nb、Ti前后的晶粒狀態. (a) 加入前；(b)加入后

Figure 11. Grain states before and after addition of Nb and Ti: (a) before addition; (b) after addition

下載: 全尺寸圖片幻燈片

圖 12 晶粒細化后的共析反應過程

Figure 12. Eutectoid reaction process after grain refinement

下載: 全尺寸圖片幻燈片

表 1 實驗鋼種的化學成分(質量分數)

Table 1. Chemical composition of the tested steel %

C Si Mn P Nb Ti Cr Al Fe

0.08 0.13 1.61 0.01 0.06 0.10 0.04 0.03 余量

下載: 導出CSV

表 2 對比鋼種的化學成分（質量分數）

Table 2. Chemical composition of comparative steel %

試樣 C Si Mn P S Nb Ti

SPHC 0.07 0.05 0.30 0.02 0.02 — —
700 L 0.08 0.13 1.61 0.01 — 0.06 0.10

下載: 導出CSV

www.77susu.com

參考文獻(16)

[1]	Cai N, Ju X H, Xing Y, et al. Study on Timicro-alloyed 700 MPa high strength automobile-beam steel. Steel Roll, 2013, 30(5): 5 doi: 10.3969/j.issn.1003-9996.2013.05.002 蔡寧, 鞠新華, 邢陽, 等. Ti微合金化700 MPa級汽車大梁鋼的研究. 軋鋼, 2013, 30(5):5 doi: 10.3969/j.issn.1003-9996.2013.05.002
[2]	Tian W Y, Liu F, Wei C H, et al. Mechanical behavior of DP980 high strength steel under dynamic tensile tests. J Mater Eng, 2017, 45(3): 47 doi: 10.11868/j.issn.1001-4381.2015.000731 田文揚, 劉奮, 韋春華, 等. DP980高強鋼動態拉伸力學行為. 材料工程, 2017, 45(3):47 doi: 10.11868/j.issn.1001-4381.2015.000731
[3]	Xing S Q, Lu H C, Ma Y L, et al. Microstructure evolution of CG-HAZ reheated by second thermal cycle for 800 MPa grade high strength steel. J Mater Eng, 2015, 43(7): 93 doi: 10.11868/j.issn.1001-4381.2015.07.016 邢淑清, 陸恒昌, 麻永林, 等. 800 MPa級高強鋼焊接粗晶區再熱循環的組織轉變規律. 材料工程, 2015, 43(7):93 doi: 10.11868/j.issn.1001-4381.2015.07.016
[4]	Zhang S Q, Feng D, Zhang Y, et al. Hot deformation behavior and constitutive model of advanced ultra-high strength hot stamping steel. J Mater Eng, 2016, 44(5): 15 doi: 10.11868/j.issn.1001-4381.2016.05.003 張施琦, 馮定, 張躍, 等. 新型超高強度熱沖壓用鋼的熱變形行為及本構關系. 材料工程, 2016, 44(5):15 doi: 10.11868/j.issn.1001-4381.2016.05.003
[5]	Tian Y Q, Zhang H J, Chen L S, et al. Comprehensive effect of C, Mn partitioning behavior on retained austenite of low carbon Si?Mn steel in I&Q&P process. J Mater Eng, 2016, 44(4): 32 doi: 10.11868/j.issn.1001-4381.2016.04.006 田亞強, 張宏軍, 陳連生, 等. 低碳硅錳鋼I&Q&P處理中C, Mn元素配分綜合作用. 材料工程, 2016, 44(4):32 doi: 10.11868/j.issn.1001-4381.2016.04.006
[6]	Yu W, Wang J, Liu T. Evolution and application of oxidation and surface quality control of hot rolled steel products. Steel Roll, 2017, 34(3): 1 余偉, 王俊, 劉濤. 熱軋鋼材氧化及表面質量控制技術的發展及應用. 軋鋼, 2017, 34(3):1
[7]	Gleeson B, Hadavi S M M, Young D J. Isothermal transformation behavior of thermally-grown wüstite. Mater High Temp, 2000, 17(2): 311 doi: 10.3184/096034000783640776
[8]	Tanei H, Kondo Y. Effects of initial scale structure on transformation behavior of wüstite. ISIJ Int, 2012, 52(1): 105 doi: 10.2355/isijinternational.52.105
[9]	Otsuka N, Doi T, Hidaka Y, et al. In-situ measurements of isothermal wüstite transformation of thermally grown FeO scale formed on 0.048 mass% Fe by synchrotron radiation in air. ISIJ Int, 2013, 53(2): 286 doi: 10.2355/isijinternational.53.286
[10]	Chen R Y, Yeun W Y D. Review of the high-temperature oxidation of iron and carbon steels in air or oxygen. OxidMet, 2003, 59(5-6): 433
[11]	Paidassi J. Sur la precipitation d'oxyde Fe₃O₄dans les pelliculesd'oxydation du fer aux temperatures elevees. Acta Metall, 1955, 3(5): 447 doi: 10.1016/0001-6160(55)90133-4
[12]	Hayashi S, Mizumoto K, Yoneda S, et al. The mechanism of phase transformation in thermally-grown FeO scale formed on pure-Fe in air. Oxid Met, 2014, 81(3-4): 357 doi: 10.1007/s11085-013-9442-7
[13]	He Y Q, Liu H Y, Sun B, et al. Structure development of oxide scale on low carbon steel strip under continue cooling conditions. Trans Mater Heat Treat, 2015, 36(1): 178 何永全, 劉紅艷, 孫彬, 等. 低碳鋼表面氧化鐵皮在連續冷卻過程中的組織轉變. 材料熱處理學報, 2015, 36(1):178
[14]	Cao G M, He Y Q, Liu X J, et al. Tertiary oxide scale structure transition of low carbon steel during continuous cooling after coiling process. J Cent South Univ Sci Technol, 2014, 45(6): 1790 曹光明, 何永全, 劉小江, 等. 熱軋低碳鋼卷取后冷卻過程中三次氧化鐵皮結構轉變行為. 中南大學學報: 自然科學版, 2014, 45(6):1790
[15]	Yoneda S, Hayashi S, Kondo Y, et al. Effect of Mn on isothermal transformation of thermally grown FeO scale formed on Fe-Mn alloys. Oxid Met, 2017, 87(1-2): 125 doi: 10.1007/s11085-016-9661-9
[16]	Yang Z H, Chen B C. Discussion of the role in microalloying elements Nb, V and Ti in steel. Gansu Metall, 2000(4): 20 楊作宏, 陳伯春. 談微合金元素Nb、V、Ti在鋼中的作用. 甘肅冶金, 2000(4):20