Abstract
The positive environmental influence of magnesium alloy usage in transportation applications could be compromised by catastrophic fast fracture caused by stress corrosion cracking (SCC). Transgranular stress corrosion cracking (TGSCC) of AZ91 has been evaluated using the linearly increasing stress test and the constant extension rate test. The TGSCC threshold stress was 55–75 MPa in distilled water and in 5 g/L NaCl. The TGSCC velocity was 7×10−10 m/s to 5×10−9 m/s. A delayed hydride-cracking model for TGSCC was implemented using a finite element script in MATLAB and the model predictions were compared with the experiment. A key outcome is that, during steady-state TGSCC propagation, a high dynamic hydrogen concentration is expected to build up behind the crack tip. In this paper, recommendations are given for preventing SCC of magnesium alloys in service. One of the most important recommendations might be that the total stress in service should be below a threshold level, which, in the absence of other data, could be estimated to be ∼50% of the tensile yield strength.
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References
G. Song and A. Atrens, “Corrosion Mechanisms of Magnesium Alloys,” Advanced Engineering Materials, 1 (1999), pp. 11–33.
G.L. Song and A. Atrens, “Understanding Magnesium Corrosion Mechanism: a Framework for Improved Alloy Performance,” Advanced Engineering Materials, 5 (2003), p. 837.
G. Song and A. Atrens, “Recent Insights into the Mechanism of Magnesium Corrosion and Research Suggestions,” Advanced Engineering Materials, 9 (2007), pp. 177–183.
A. Atrens and W. Dietzel, “The Negative Difference Effect and Unipositive Mg+”, Advanced Engineering Materials 9 (2007) PP. 292–297.
J.X. Jia, G.L. Song, and A. Atrens, “Influence of Geometry on Galvanic Corrosion of AZ91D Coupled to Steel,” Corrosion Science, 48 (2006), pp. 2133–2153.
J.X. Jia, G. Song, and A. Atrens, “Experimental Measurement and Computer Simulation of Galvanic Corrosion of Magnesium Coupled to Steel,” Advanced Engineering Materials, 9 (2007), pp. 65–74.
G.L. Song, A. Atrens, and M. Dargusch, “Influence of Microstructure on the Corrosion of Diecast AZ91D,” Corrosion Science, 41 (1999), pp. 249–273.
G.L. Song et al., “Corrosion Behaviour of AZ21, AZ501, and AZ91 in Sodium Chloride,” Corrosion Science, 40 (1998), pp. 1769–1791.
G.L. Song et al., “Electrochemical Corrosion of Pure Magnesium in 1N NaCl,” Corrosion Science, 39 (1997), pp. 855–875.
G.L. Song et al., “The Anodic Dissolution of Magnesium in Chloride and Sulphate Solutions,” Corrosion Science, 39 (1997), pp. 1981–2004.
Z. Shi, G. Song, and A. Atrens, “The Corrosion Performance of Anodized Magnesium Alloys,” in Ref. 5, pp. 3531–3546.
Z. Shi, G.L. Song, and A. Atrens, “Influence of Anodizing Current on the Corrosion Resistance of Anodized AZ91D Magnesium Alloy,” in Ref. 5, pp. 1939–1959.
Z. Shi, G.L. Song, and A. Atrens, “Corrosion Resistance of Anodized Single-Phase Mg Alloys,” Surface and Coatings Technology, 201 (2006), pp. 492–500.
J.X. Jia, G. Song, and A. Atrens, “Boundary Element Predictions of the Influence of the Electrolyte on the Galvanic Corrosion of AZ91D Coupled to Steel,” Materials and Corrosion, 56 (2005), pp. 259–270.
J.X. Jia et al., “Simulation of Galvanic Corrosion of Magnesium Coupled to a Steel Fastener in NaCl Solution,” Materials and Corrosion, 56 (2005), pp. 468–474.
Z. Shi, G. Song, and A. Atrens, “Influence of the β Phase on the Corrosion Performance of Anodized Coatings on Magnesium-Aluminum Alloys,” Corrosion Science, 47 (2005), pp. 2760–2777.
A. Atrens, “Suggestions for Research Directions in Magnesium Corrosion Arising from the Wolfsburg Conference,” Advanced Engineering Materials, 6 (2004), pp. 83–84.
N. Winzer et al., “A Critical Review of the Stress Corrosion Cracking (SCC) of Magnesium Alloys,” Advanced Engineering Materials, 7 (2005), pp. 659–693.
N. Winzer et al., “Comparison of the Linearly Increasing Stress Test and the Constant Extension Rate Test in the Evaluation of Transgranular Stress Corrosion Cracking of Magnesium,” Materials Science and Engineering A (accepted for publication, 2007).
N. Winzer et al., “Evaluation of Mg SCC using LIST and SSRT” (Presentation at the 7th International Conference on Magnesium Alloys and Their Applications, Dresden, Germany, November 2006).
N. Winzer et al., “Stress Corrosion Cracking of Mg” (Invited Keynote Paper at the 3rd International Conference on Environmental Degradation of Engineering Materials, Gdansk, Poland, May 2007).
R.G. Song et al., “A Study of the Stress Corrosion Cracking and Hydrogen Embrittlement of AZ31 Magnesium Alloy,” Materials Science and Engineering, 399 (2005), pp. 308–317.
M.B. Kannan et al., “SCC Evaluation of Mg Alloys AZ80, ZE41, QE22 and EV21,” Materials Science and Engineering (accepted for publication, 2007).
N. Winzer et al., “Evaluation of the Delayed Hydride Cracking Mechanism for Transgranular Stress Corrosion Cracking of Magnesium Alloys,” Materials Science and Engineering A, 466 (2007), pp. 18–31.
A. Atrens et al., “Stress Corrosion Cracking and Hydrogen Diffusion in Magnesium,” Advanced Engineering Materials, 8 (2006), pp. 749–751.
A.J. Bursle and E.N. Pugh, Mechanisms of Environment Sensitive Cracking of Materials, ed. P.R. Swann, F.P. Ford, and A.R.C. Westwood (London: Materials Society, 1977), p. 471.
D.G. Chakrapani and E.N. Pugh, Metallurgical Transactions, 6A (1975), p. 1155.
D.G. Chakrapani and E.N. Pugh, Corrosion, 31 (1975), p. 247.
D.G. Chakrapani, E.N. Pugh, 7A, Metallurgical Transactions 7A (1976) p. 173.
E.H. Pugh, J.A.S. Green, and P.W. Slattery, Fracture 1969: The Proceedings of the Second International Conference on Fracture, ed. P.L. Pratt (London: Chapman and Hall Ltd., 1969), p. 387.
K. Ebtehaj, D. Hardie, and R.N. Parkins, Corrosion Science, 28 (1993), p. 811.
R.S. Stampella, R.P.M. Procter, and V. Ashworth, Corrosion Science, 24 (1984), p. 325.
G.L. Makar, J. Kruger, and K. Sieradzki, Corrosion Science, 34 (1993), p. 1311.
A. Atrens et al., “Linearly Increasing Stress Test (LIST) for SCC Research,” Meas. Sci. Technol., 4 (1993), pp. 1281–1292.
S. Ramamurthy and A. Atrens, “The Stress Corrosion Cracking of As-Quenched 4340 and 3.5NiCrMoV Steels Under Stress Rate Control in Distilled Water at 90°C,” Corrosion Science, 34 (1993), pp. 1385–1402.
Z.F. Wang and A. Atrens, “Initiation of Stress Corrosion Cracking for Pipeline Steels in a Carbonate-Bicarbonate Solution,” Metallurgical and Materials Transactions, 27A (1996), pp. 2686–2691.
J. Salmond and A. Atrens, “SCC of Copper Using the Linearly Increasing Stress Test,” Scripta Metallurgica et Materialia, 26 (1992), pp. 1447–1450.
A. Atrens and A. Oehlert, “Linearly Increasing Stress Test (LIST) of Carbon Steel in 4N NaNO3 and in Bayer Liquor,” J. Materials Science, 33 (1998), pp. 783–788.
J. Wang and A. Atrens, “SCC Initiation for X65 Pipeline Steel in “High” pH Carbonate/Bicarbonate Solution,” Corrosion Science, 45 (2003), pp. 2199–2217.
J.Q. Wang and A. Atrens, “Analysis of Service Stress Corrosion Cracking in a Natural Gas Transmission Pipeline: Active or Dormant?” Engineering Failure Analysis, 11 (2004), pp. 3–18.
E. Gamboa and A. Atrens, “Material Influence on the Stress Corrosion Cracking of Rock Bolts,” Engineering Failure Analysis, 12 (2005), pp. 201–225.
E. Gamboa and A. Atrens, “Environmental Influence on the Stress Corrosion Cracking of Rock Bolts,” Engineering Failure Analysis, 10 (2003), pp. 521–558.
A. Oehlert and A. Atrens, “Stress Corrosion Crack Propagation in AerMet 100,” J. Mater. Sci., 33 (1998), pp. 775–781.
A. Oehlert and A. Atrens, “Environmental Assisted Fracture for 4340 Steel in Water and Air of Various Humidities,” J. Mater. Sci., 32 (1997), pp. 6519–6523.
A. Oehlert and A. Atrens, “The Initiation and Propagation of Stress Corrosion Cracking in AISI 4340 and 3.5 Ni-Cr-Mo-V Rotor Steel in Constant Load Tests,” Corros. Sci., 38 (1996), pp. 1159–1170.
A. Oehlert and A. Atrens, “Room Temperature Creep of High Strength Steels,” Acta Metall. Mater., 42 (1994), pp. 1493–1508.
W. Dietzel and K.H. Schwalbe, “Monitoring Stable Crack Growth Using a Combined A.C./D.C. Potential Drop Technique,” Z. Materialprüfung, 28(11) (1986), pp. 368–372.
W.R. Wearmouth, G.P. Dean, and R.N. Parkins, “Role of Stress in the Stress Corrosion Cracking of a Mg-Al Alloy,” Corrosion, 29(6) (1979), pp. 251–258.
S.P. Lynch and P. Trevena, “Stress Corrosion Cracking and Liquid Metal Embrittlement in Pure Magnesium,” Corrosion, 44 (1988), pp. 113–124.
M.O. Speidel et al., “Corrosion Fatigue and Stress Corrosion Crack Growth in High Strength Aluminium Alloys, Magnesium Alloys and Titanium Alloys Exposed to Aqueous Solutions,” Corrosion Fatigue: Chemistry, Mechanics and Microstructure, NACE-2 (1972), pp. 324–345.
A. Atrens and Z.F. Wang, Materials Forum, 19 (1995), p. 9.
W. Dietzel, Encyclopedia of Materials: Science and Technology, ed. K.H.J. Buschow et al. (Amsterdam: Elsevier Science Ltd., 2001), p. 8883.
R.M. Rieck, A. Atrens, and I.O. Smith, “The Role of Crack Tip Strain Rate in the Stress Corrosion Cracking of High Strength Steels in Water,” Met. Trans. A, 20A (1989), pp. 889–895.
W.K. Miller, Mat. Res. Soc. Symp. Proc., 125 (1988), p. 253.
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Winzer, N., Atrens, A., Dietzel, W. et al. Stress corrosion cracking in magnesium alloys: Characterization and prevention. JOM 59, 49–53 (2007). https://doi.org/10.1007/s11837-007-0104-6
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DOI: https://doi.org/10.1007/s11837-007-0104-6