Microstructure and Corrosion Behavior of Fe-15Mn-5Si-14Cr-0.2C Amorphous Steel
ZHAO Yanchun1,2(), MAO Xuejing1, LI Wensheng1, SUN Hao1, LI Chunling3, ZHAO Pengbiao1, KOU Shengzhong1, Liaw Peter K.2
1.State Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metals, Lanzhou University of Technology, Lanzhou 730050, China 2.Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996-2200, USA 3.College of Mechano-Electronic Engineering, Lanzhou University of Technology, Lanzhou 730050, China
Cite this article:
ZHAO Yanchun, MAO Xuejing, LI Wensheng, SUN Hao, LI Chunling, ZHAO Pengbiao, KOU Shengzhong, Liaw Peter K.. Microstructure and Corrosion Behavior of Fe-15Mn-5Si-14Cr-0.2C Amorphous Steel. Acta Metall Sin, 2020, 56(5): 715-722.
Amorphous steels exhibit ultra-high strength but room-temperature brittleness and strain-softening behavior as loading, which restricted the application of amorphous steels as high-performance structural material. Developing in situ crystals is an effective way to toughen the amorphous alloys. However, the crystals may sacrifice the corrosion resistance of amorphous steels. In this work, austenite and ferrite duel phases were introduced to the amorphous phase, via transformation induced plasticity (TRIP) of the austenite as loading, to enhance the ductility and improve the work-hardening behavior; and via the synergy of ferrite and amorphous phase to ensure the corrosion resistance. A novel amorphous steel Fe-15Mn-5Si-14Cr-0.2C was fabricated by magnetic suspension melting in a water-cooled copper crucible, and negative pressure suction casting into a copper mold. The microstructure and mechanical properties of the amorphous steel were characterized by XRD, EBSD and the electronic universal testing machine. The corrosion behavior in artificial seawater was studied on an electrochemical work station with a three-electrode system, and the corrosion morphology and corrosion products were characterized by SEM with EDS analysis. The results showed that the as-cast amorphous steel consisted of the amorphous matrix, CFe15.1 super-cooled austenite and Fe-Cr ferrite phases. From surface to inner, amorphous phases mainly exist in the margin, while crystalline phases are abundantly distributed in the center. The amorphous steel exhibited excellent comprehensive mechanical properties at room temperature, and its yield strength, fracture strength and plastic strain were up to 978 MPa, 2645 MPa and 35.8%, respectively. In artificial seawater, compared with 304 stainless steel, the amorphous steel showed high self-corrosion potential, low self-corrosion current density and high polarization resistance, large resistance arc radius, only one high frequency resistance arc and low corrosion kinetic rate. Moreover, the stable and dense passivation film was observed on the corrosion surface. Their excellent corrosion resistance and mechanical properties endow the amorphous steel with the potential to become a novel corrosion-resistant structural material for marine engineering.
Fund: National Natural Science Foundation of China(51661017);China Scholarship Council(201808625027);Outstanding Youth Funds of Gansu Province(17JR5RA108);Hongliu Outstanding Youth Funds of Lanzhou University of Technology
Fig.1 XRD spectra of as-cast Fe-15Mn-5Si-14Cr-0.2C sample and fractured sample after loading
Fig.2 Engineering stress-strain curve of as-cast Fe-15Mn-5Si-14Cr-0.2C sample at room temperature
Fig.3 EBSD images of as-cast Fe-15Mn-5Si-14Cr-0.2C sample in edge zone (a), center zone (b) and fractured sample after loading (c)
Fig.4 Potentiodynamic polarization curves of Fe-15Mn-5Si-14Cr-0.2C alloy and 304 stainless steel in artificial seawater at 298 K (i—current density)
Alloy
Ecorr
mV
icorr
μA·cm-2
Rp
106 Ω·cm2
Epit
mV
Epit-Ecorr
mV
304 stainless steel
-263.43
1.582
2.2
384.93
648.41
Fe-15Mn-5Si-14Cr-0.2C
-211.85
0.490
8.9
598.58
810.43
Table 1 Corrosion parameters of Fe-15Mn-5Si-14Cr-0.2C alloy and 304 stainless steel in artificial seawater at 298 K
Fig.5 AC impedance diagrams of Fe-15Mn-5Si-14Cr-0.2C alloy and 304 stainless steel in artificial seawater at 298 K (Zim—imaginative part of impedance, Zre—real part of impedance)
Fig.6 SEM images of Fe-15Mn-5Si-14Cr-0.2C alloy after electrochemical corrosion at margin (a) and center (b) areas
Area
Fe
Mn
Si
Cr
C
Margin
56.54
7.32
15.49
6.15
14.50
Center
58.80
11.60
6.58
8.27
14.75
Table 2 EDS analyses of Fe-15Mn-5Si-14Cr-0.2C alloy after electrochemical corrosion at margin and center areas
Fig.7 SEM-BS image of Fe-15Mn-5Si-14Cr-0.2C after electrochemical corrosion
1
Inoue A. High strength bulk amorphous alloys with low critical cooling rates (Overview) [J]. Mater. Trans., 1995, 36: 866
2
Hofmann D C. Shape memory bulk metallic glass composites [J]. Science, 2010, 329: 1294
doi: 10.1126/science.1193522
pmid: 20829474
3
Qiao J C, Wang Q, Pelletier J M, et al. Structural heterogeneities and mechanical behavior of amorphous alloys [J]. Prog. Mater. Sci., 2019, 104: 250
4
Wang W H. The nature and properties of amorphous matter [J]. Prog. Phys., 2013, 33(5): 177
汪卫华. 非晶态物质的本质和特性 [J]. 物理学进展, 2013, 33(5): 177
5
Pan J, Zhang M, Chen Q, et al. Study of anticorrosion ability of Fe43.7Co7.3Cr14.7Mo12.6C15.5B4.3Y1.9 bulk metallic glass in strong acid solutions [J]. Rare Met. Mater. Eng., 2008, 37: 805
Fan H B, Zheng W, Wang G Y, et al. Corrosion behavior of Fe41Co7Cr15Mo14C15B6Y2 bulk metallic glass in sulfuric acid solutions [J]. Metall. Mater. Trans., 2011, 42A: 1524
7
Gostin P F, Gebert A, Schultz L. Comparison of the corrosion of bulk amorphous steel with conventional steel [J]. Corros. Sci., 2010, 52: 273
8
Naka M, Hashimoto K, Inoue A, et al. Corrosion-resistant amorphous Fe-C alloys containing chromium and/or molybdenum [J]. J. Non-Cryst. Solids, 1979, 31: 347
9
Jayaraj J, Kim K B, Ahn H S, et al. Corrosion mechanism of N-containing Fe-Cr-Mo-Y-C-B bulk amorphous alloys in highly concentrated HCl solution [J]. Mater. Sci. Eng., 2007, A449-451: 517
10
Pardo A, Merino M C, Otero E, et al. Influence of Cr additions on corrosion resistance of Fe- and Co-based metallic glasses and nanocrystals in H2SO4 [J]. J. Non-Cryst. Solids, 2006, 352: 3179
11
Chen J, Wang J Z, Chen B B, et al. Tribocorrosion behaviors of Inconel 625 alloy sliding against 316 steel in seawater [J]. Tribol. Trans., 2010, 54: 514
12
Hu X F, Jiang H C, Zhao M J, et al. Microstructure and mechanical properties of welded joint of a Fe-Cr-Ni-Mo steel with high-strength and high-toughness [J]. Acta Metall. Sin., 2018, 54: 1
Hakiki N B, Boudin S, Rondot B, et al. The electronic structure of passive films formed on stainless steels [J]. Corros. Sci., 1995, 37: 1809
14
Zhi J H, Wang Y, Li J H, et al. Microsturcture and high temperature mechanical properties of martensitic stainless steel [J]. Heat Treat. Met., 2018, 43(3): 68
Cao C N. Principles of Electrochemistry of Corrosion [M]. Beijing: Chemical Industry Press, 2008: 99
曹楚南. 腐蚀电化学原理 [M]. 北京: 化学工业出版社, 2008: 99
16
Stern M, Geary A L. Electrochemical polarization I. A theoretical analysis of the shape of polarization curves [J]. J. Electrochem. Soc., 1957, 104: 56
17
Li J W, Yang L J, Ma H R, et al. Improved corrosion resistance of novel Fe-based amorphous alloys [J]. Mater. Des., 2016, 95: 225
doi: 10.1016/j.actbio.2016.03.047
pmid: 27045349
18
Hua N B, Chen W Z, Wang Q T, et al. Tribocorrosion behaviors of a biodegradable Mg65Zn30Ca5 bulk metallic glass for potential biomedical implant applications [J]. J. Alloys Compd., 2018, 745: 111
19
Wen P, Li C F, Zhao Y, et al. First principles calculation of occupancy, bonding characteristics and alloying effect of Cr, Mo, Ni in bulk α-Fe(C) [J]. Acta Phys. Sin., 2014, 63(19): 197101
Li L, Xing S B. Catalytic effect analysis of metallic catalyst during diamond single crystal synjournal [J]. Acta Metall. Sin. (Engl. Lett)., 2014, 27: 161
21
Wang Y F, Li Y K, Sun C, et al. Electronic theoretical model of static and dynamic strength of steels [J]. Acta Phys. Sin., 2014, 63(12): 126101
Wang Y, Li C F, Lin Y H. Electronic theoretical study of the influence of Cr on corrosion resistance of Fe-Cr Alloy [J]. Acta Metall. Sin., 2017, 53: 622
Souza C A C, Ribeiro D V, Kiminami C S. Corrosion resistance of Fe-Cr-based amorphous alloys: An overview [J]. J. Non-Cryst. Solids, 2016, 442: 56
24
Huang C B, Lu Z P, Yang W. Anodic dissolution and passiyation of an Fe-Ni base alloy in hot concentrated caustic solutions [J]. Corros. Sci. Pro. Technol., 2001, 13(Suppl.): 514
Chen P, Qin F X, Zhang H F, et al. Corrosion behaviors of bulk amorphous alloy Cu-Zr-Ti-Sn and its crystallized form in 3.5% NaCl solution [J]. Acta Metall. Sin., 2004, 40: 207
Hu Y P, Ping K B, Yan Z J, et al. First-principles calculations of structure and magnetic properties of α-Fe(Si) phase precipitated in the Finemet alloy [J]. Acta Phys. Sin., 2011, 60(10): 107504
Han Y, Kong F L, Han F F, et al. New Fe-based soft magnetic amorphous alloys with high saturation magnetization and good corrosion resistance for dust core application [J]. Intermetallics, 2016, 76: 18
28
Machmeier P, Matuszewski T, Jones R, et al. Effect of chromium additions on the mechanical and physical properties and microstructure of Fe-Co-Ni-Cr-Mo-C ultra-high strength steel: Part I [J]. J. Mater. Eng. Perform., 1997, 6: 279
29
Botta W J, Berger J E, Kiminami C S, et al. Corrosion resistance of Fe-based amorphous alloys [J]. J. Alloys Compd., 2014, 586(Suppl. 1): S105
30
Qu S P, Cheng B Z, Dong L H, et al. Corrosion behavior of 2205 steel in simulated hydrothermal area [J]. Acta Metall. Sin., 2018, 54: 1094
