New insights into the mechanism of localised corrosion induced by TiN-containing inclusions in high strength low alloy steel

doi:10.1016/j.jmst.2021.12.075

Abstract

Abstract:

This work investigated the chemical and electrochemical mechanisms of localised corrosion triggered by CaS·xMgO·yAl₂O₃·TiN complex inclusions in high strength low alloy steel (HSLAS) under a simulated marine environment. Special focus was given to the role of the TiN portion of the inclusion on the initiation and growth of the corrosion pits. The thermodynamic process of pitting initiation was investigated by Gibbs free energy, Pourbaix diagram and first principle calculation. Localised corrosion is mainly induced by inclusions and triggered by dissolution of adjacent distorted matrix. Chemical dissolution of CaS portion in CaS·xMgO·yAl₂O₃·TiN complex inclusion creates an acidic aggressive environment that accelerates the further dissolution of inclusion and matrix. Galvanic coupling effect between TiN inclusion and matrix is directly verified. TiN covered with a TiO₂ film acts as the cathodic phase in galvanic corrosion, although it has a lower Volta potential than the matrix. This is an unusual correlation with the scanning Kelvin probe force microscopy result, which has been explained for this special system.

Key words: High strength low alloy steel, TiN-containing inclusion, Localised corrosion, Pourbaix diagram, First principle calculation

Chao Liu, Reynier I. Revilla, Xuan Li, Zaihao Jiang, Shufeng Yang, Zhongyu Cui, Dawei Zhang, Herman Terryn, Xiaogang Li. New insights into the mechanism of localised corrosion induced by TiN-containing inclusions in high strength low alloy steel[J]. J. Mater. Sci. Technol., 2022, 124: 141-149.

Figures/Tables 11

Table 1. Chemical composition of E690 steel (wt.%).

C	Si	Mn	P	S	Cr	Ni	Cu
0.114	0.203	1.056	0.0076	0.002	0.462	1.185	0.016
Al	Ti	Mo	V	Ca	O	N	Fe
0.038	0.011	0.484	0.033	0.0017	0.0012	0.0035	Bal.

Fig. 1. Secondary electron microscopy image and EDS mapping of inclusions in the specimen CaS·xMgO·yAl2O3·TiN.

Fig. 2. (a) Morphology and DES maps of CaS·xMgO·yAl2O3·TiN in the polished specimen, (b) AFM topography (c) SKPFM maps, (d) CSAFM maps of the same area in (a); (e-g) the strip profile analyses for the selected inclusions.

Fig. 3. Localised corrosion morphology and EDS mapping on E690 steel after immersion for (a) 1 min, (b) 2 min, (c) 30 min and (d) 12 h.

Table 2. Standard Gibbs free energies of possible reactions during inclusion dissolution at 298 K [28], [29], [30], [31], [32].

Chemical reaction	ΔG_f^° (kJ/mol)
$Fe + H 2 O + 1 / 2 O 2 → Fe OH 2$	-203.92
$Fe + 2 HCl + 1 / 2 O 2 → FeCl 2 + H 2 O$	-444.10
$CaS + H 2 O + CO 2 → CaCO 3 + H 2 S$	- 53.60
$CaCO 3 + 2 HCl → CaCl 2 + H 2 O + CO 2$	-59.90
$MgO · Al 2 O 3 + 8 HCl → MgCl 2 + 2 AlCl 3 + 4 H 2 O$	-1852.12
$MgO · Al 2 O 3 + H 2 O → Mg OH 2 + Al 2 O 3$	+ 62.44
$TiN + 4 H 2 O → Ti OH 4 + 1 / 2 N 2 + 2 H 2$	+321.23
$TiN + 5 H 2 O → Ti OH 4 + NO + 3 H 2$	-2.51
$TiN + 2 O 2 → TiO 2 + 1 / 2 N 2$	-611.8

Table 2. Standard Gibbs free energies of possible reactions during inclusion dissolution at 298 K [28], [29], [30], [31], [32].

Chemical reaction	ΔG_f^° (kJ/mol)
$Fe + H 2 O + 1 / 2 O 2 → Fe OH 2$	-203.92
$Fe + 2 HCl + 1 / 2 O 2 → FeCl 2 + H 2 O$	-444.10
$CaS + H 2 O + CO 2 → CaCO 3 + H 2 S$	- 53.60
$CaCO 3 + 2 HCl → CaCl 2 + H 2 O + CO 2$	-59.90
$MgO · Al 2 O 3 + 8 HCl → MgCl 2 + 2 AlCl 3 + 4 H 2 O$	-1852.12
$MgO · Al 2 O 3 + H 2 O → Mg OH 2 + Al 2 O 3$	+ 62.44
$TiN + 4 H 2 O → Ti OH 4 + 1 / 2 N 2 + 2 H 2$	+321.23
$TiN + 5 H 2 O → Ti OH 4 + NO + 3 H 2$	-2.51
$TiN + 2 O 2 → TiO 2 + 1 / 2 N 2$	-611.8

Fig. 4. Pourbaix diagram of the Fe-Ca-S-H2O and Ti-N-H2O systems at 298.15 K calculated by Factsage software.

Fig. 5. (a) Secondary electron microscopy image and EDS result of TiN inclusion, TEM images and the SAD results of the TiN inclusion (b) and interface between TiN inclusion and SiO2 (c), (d) XPS spectra of TiO2 2p3/2 and TiO2 2p1/2 peaks of the passive films formed on pure Ti specimen, (e) AFM topography and CSAFM map of pure Ti specimen, and (f) line profile analyses for the selected area in (e).

Fig. 6. Possible suspected structures of CaS, xMgO·yAl2O3, TiN and Fe.

Table 3. Work function and surface energy of CaS, xMgO·yAl2O3, TiN and Fe.

Crystallographic		WF=LP-E-Fermi (eV)	Surface energy (J/m²)	Crystallographic		WF=LP-E-Fermi (eV)	Surface energy (J/m²)
CaS	100	4.819	1.671	TiO₂	100	6.787	2.179
Empty Cell	110	4.398	1.832		110	9.362	0.966
Empty Cell	111	8.755	2.492		111	6.501	1.636
MgAl₂O₄	100	4.565	3.901	Fe	100	4.452	2.670
Empty Cell	110	5.722	3.582		110	5.184	2.511
Empty Cell	111	8.693	3.019		111	4.480	2.857
TiN	100	2.928	1.294
Empty Cell	110	3.139	2.663
Empty Cell	111	6.770	3.417

Table 4. Physical properties of different components in the inclusions and the carbon steel.

Compounds	Thermal expansion coefficient (× 10^-6/°C)	Electrical volume resistance (Ω·cm at 20 °C)	Refs.
Al₂O₃	8.2	8 × 10¹⁵	[36,39]
CaS	14.7	>10¹³	[40,41]
MgO·Al₂O₃	8.4	>10¹⁵	[41,42]
TiN	9.4	27	[40,41]
Ti₂O	8.4	74	[40,41]
Carbon steel	10.8	1 × 10^-5	[42,43]

Fig. 7. Schematics of localised corrosion initiation induced by CaS·xMgO·yAl2O3·TiN inclusion.

References 50

[1]	B. Beidokhti, A.H. Koukabi, A. Dolati, Mater. Charact. 60 (2009) 225-233. DOI URL
[2]	A.J. Haq, K. Muzaka, D.P. Dunne, A. Calka, E.V. Pereloma, Int. J. Hydrog. Energy 38 (2013) 2544-2556. DOI URL
[3]	C. Liu, X. Li, R.I. Revilla, T. Sun, J. Zhao, D. Zhang, S. Yang, Z. Liu, X. Cheng, H. Terryn, X. Li, Corros. Sci. 179 (2021) 109150. DOI URL
[4]	C. Liu, Z. Jiang, J. Zhao, X. Cheng, Z. Liu, D. Zhang, X. Li, Corros. Sci. 166 (2020) 108463. DOI URL
[5]	T.Y. Jin, Y.F. Cheng, Corros. Sci. 53 (2011) 850-853. DOI URL
[6]	I.J. Park, S.M. Lee, M. Kang, S. Lee, Y.K. Lee, J. Alloy. Compd. 619 (2015) 205-210. DOI URL
[7]	W. Xue, Z. Li, K. Xiao, W. Yu, J. Song, J. Chen, C. Dong, X. Li, Corros. Sci. 163 (2020) 108232. DOI URL
[8]	H. Su, S. Wei, Y. Liang, Y. Wang, B. Wang, Y. Yuan, J. Electroanal. Chem. 863 (2020) 114056. DOI URL
[9]	Y. Hou, T. Li, G. Li, C. Cheng, Micron 130 (2020) 102820. DOI URL
[10]	C. Liu, R.I. Revilla, D. Zhang, Z. Liu, A. Lutz, F. Zhang, T. Zhao, H. Ma, X. Li, H. Terryn, Corros. Sci. 138 (2018) 96-104. DOI URL
[11]	C. Liu, R.I. Revilla, Z. Liu, D. Zhang, X. Li, H. Terryn, Corros. Sci. 129 (2017) 82-90. DOI URL
[12]	D. Kong, C. Dong, X. Ni, L. Zhang, J. Yao, C. Man, X. Cheng, K. Xiao, X. Li, J. Mater. Sci. Technol. 35 (2019) 1499-1507. DOI URL
[13]	G. Li, L. Wang, H. Wu, C. Liu, X. Wang, Z. Cui, Corros. Sci. 174 (2020) 108815. DOI URL
[14]	R.S. Dutta, R. Tewari, P.K. De, Corros. Sci. 49 (2007) 303-318. DOI URL
[15]	J. Tan, X. Wu, E.H. Han, W. Ke, X. Liu, F. Meng, X. Xu, Corros. Sci. 88 (2014) 349-359. DOI URL
[16]	H. Chen, L. Lu, Y. Huang, X. Li, J. Mater. Res. Technol. 13 (2021) 13-24. DOI URL
[17]	W. Wei, K. Wu, X. Zhang, J. Liu, P. Qiu, L. Cheng, J. Mater. Res. Technol. 9 (2020) 1412-1424. DOI URL
[18]	X.H. Li, F. Huang, J.Q. Wang, E.H. Han, K. Wei, J. Mater. Sci. Technol. 47 (2011) 847-852.
[19]	F. Meng, J. Wang, E.H. Han, W. Ke, Corros. Sci. 52 (2010) 927-932. DOI URL
[20]	M.B. Leban, R. Tisu, Eng. Fail. Anal. 33 (2013) 430-438. DOI URL
[21]	S.L. Yun, J.S. Kim, H.S. Kwon, J. Nucl. Mater. 336 (2005) 65-72. DOI URL
[22]	Y. Ji, C. Dong, D. Kong, X. Li, J. Mater. Sci. Technol. 46 (2020) 145-155. DOI URL
[23]	M. Iannuzzi, K.L. Vasanth, G.S. Frankel, J. Electrochem. Soc. 164 (2017) C488-C497. DOI URL
[24]	V. Yakubov, M. Lin, A.A. Volinsky, L. Qiao, L. Guo, npj Mater. Degrad. 2 (2018) 1-4. DOI URL
[25]	H. Ma, X.Q. Chen, R. Li, S. Wang, J. Dong, W. Ke, Acta Mater. 130 (2017) 137-146. DOI URL
[26]	R.I. Revilla, J. Liang, S. Godet, I.D. Graeve, J. Electrochem. Soc. 162 (2017) C27-C35.
[27]	N. Sathirachinda, R. Pettersson, S. Wessman, J. Pan, Corros. Sci. 52 (2010) 179-186. DOI URL
[28]	B. Avasarala, P. Haldar, Electrochim. Acta 55 (2010) 9024-9034. DOI URL
[29]	S.D. Chyou, H.C. Shih, T.T. Chen, Corros. Sci. 35 (1993) 337-347. DOI URL
[30]	A.G. Tyurin, I.Y. Pyshmintsev, I.V. Kostitsyna, I.M. Zubkova, Prot. Met. 43 (2007) 34-44. DOI URL
[31]	M.W. Chase Jr, J. Phys. Chem. Ref Data Monogr. (1998).
[32]	C. Yue, S. Li, K. Ding, N. Zhong, Geochem. J. 40 (2006) 87-94. DOI URL
[33]	Z.Y. Zhou, N. Tian, J.T. Li, I. Broadwell, S.G. Sun, Chem. Soc. Rev. 40 (2011) 4167-4185. DOI URL
[34]	Y. Jin, M. Liu, C. Zhang, C. Leygraf, L. Wen, J. Pan, J. Electrochem. Soc. 164 (2017) C465-C473. DOI URL
[35]	K. Tanaka, T. Mura, Metall. Trans. A 13 (1982) 117-123. DOI URL
[36]	L. Wang, J. Xin, L. Cheng, K. Zhao, B. Sun, J. Li, X. Wang, Z. Cui, Corros. Sci. 147 (2019) 108-127. DOI URL
[37]	H. Huang, H. Wang, J. Zhang, D. Yan, Appl. Phys. A 95 (2009) 125-130. DOI URL
[38]	P. Liu, Q. Zhang, X. Li, J. Hu, F. Cao, J. Mater. Sci. Technol. 64 (2021) 99-113. DOI URL
[39]	R. Bäßler, Materials Handbook-A Concise Desktop Reference, Springer, 2020.
[40]	P. Juvonen, Effects of Non-Metallic Inclusions On Fatigue Properties of Calcium Treated Steels, Ph.D. Thesis. Helsinki University of Technology, 2004.
[41]	R. Riedel, Handbook of Ceramic Hard Materials, WILEY-VCH Verlag GmbH, 2000.
[42]	D. Brooksbank, K. Andrews, in: Proceedings of the Production and Application of Clean Steels, 1972, pp. 186-198.
[43]	C. Leung, L. Van Vlack, Metall. Trans. A 12 (1981) 987-991. DOI URL
[44]	D. Dwivedi, K. Lepková, T. Becker, RSC Adv. 7 (2017) 4580-4610. DOI URL
[45]	E. Rafiee, M. Farzam, M.A. Golozar, A. Ashrafi, ISRN Corros. 2013 (2013) 1-6, 921825.
[46]	C. Escrivà-Cerdán, S.W. Ooi, G.R. Joshi, R. Morana, H.K.D.H. Bhadeshia, R. Akid, Corros. Sci. 154 (2019) 36-48. DOI URL
[47]	X. Guo, S. Gin, P. Lei, T. Yao, H. Liu, D.K. Schreiber, D. Ngo, G. Viswanathan, T. Li, S.H. Kim, J.D. Vienna, J.V. Ryan, J. Du, J. Lian, G.S. Frankel, Nat. Mater. 19 (2020) 310-316. DOI URL
[48]	B. Munirathinam, R. Narayanan, L. Neelakantan, Thin Solid Films 598 (2016) 260-270. DOI URL
[49]	S.P. Harrington, T. Devine, ECS Trans. 16 (2009) 117-123.
[50]	Y. Wang, G. Cheng, W. Wu, Q. Qiao, Y. Li, X. Li, Appl. Surf. Sci. 349 (2015) 746-756. DOI URL