Stress corrosion cracking aluminum

D.O. Sprowls, High strength aluminium alloys with improved resistance to corrosion and stress corrosion cracking. Aluminum 54(3), 214 217 (1978). 

Materials of Construction. GeneraHy, carbon steel is satisfactory as a material of construction when handling propylene, chlorine, HCl, and chlorinated hydrocarbons at low temperatures (below 100°C) in the absence of water. Nickel-based aHoys are chiefly used in the reaction area where resistance to chlorine and HCl at elevated temperatures is required (39). Elastomer-lined equipment, usuaHy PTFE or Kynar, is typicaHy used when water and HCl or chlorine are present together, such as adsorption of HCl in water, since corrosion of most metals is excessive. Stainless steels are to be avoided in locations exposed to inorganic chlorides, as stainless steels can be subject to chloride stress-corrosion cracking. Contact with aluminum should be avoided under aH circumstances because of potential undesirable reactivity problems. 

Aluminum and silicon bronzes are very popular in the process industries because they combine good strength with corrosion resistance. Copper-beryllium alloys offer the greatest strength and excellent corrosion resistance in seawater and are resistant to stress-corrosion cracking in hydrogen sulfide. 

Tests for aluminum and its alloys consist of intergranular corrosion, stress corrosion cracking and corrosion fatigue as detailed below ... 

M.J. Blackburn, W.H. Smyrl, J.A. Feeney and B.F. Brown (eds.), Stress-Corrosion Cracking on High Strength Steel and in Titanium and Aluminum Alloys, Naval Research Laboratory, Washington, DC, 1972, pp. 245-363. 

The aluminum cylinder is constantly under pressure and this is believed to be a contributing factor for stress corrosion cracking (SCC). 

Stress corrosion cracking (see also in Section 8.6 in pressurized ammonia vessels and tanks is a problem which has been discussed in many papers [1252]-[1265], [1271]-[1276], The mechanism of this phenomenon, the influence of water, and the role of oxygen are not yet completely understood, in spite of extensive research. A review is given in [1277]. As it is generally accepted that addition of water may inhibit stress corrosion [1263], [1264] it has become a widely used practice to maintain a water content of 0.2% in transport vessels [1264]. Protection may also be achieved by aluminum or zinc metal spray coating [1275], [1277], More recent research [1273], [1277], however, has shown that water may not give complete protection. 

Fig. 7.90 Effect of stressing direction on the intergranular stress-corrosion crack path in susceptible high-strength aluminum alloy. Dark boundaries are representative of ones favored for cracking for indicated direction of applied stress. Source Ref 97...

Fig. 7.113 Dependence of stress-corrosion-crack-growth rate on stress intensity of a high-strength aluminum alloy in several aqueous environments. Crack orientation TL (stress in transverse direction crack propagation in longitudinal direction). Source Ref 159...

A.J. Sedricks, J.A. Green, and J. Novak, Corrosion Processes and Solution Chemistry within Stress Corrosion Cracks in Aluminum Alloys, Localized Corrosion NACE 3, R.W. Staehle, B.F. Brown, J. Kruger, and A. Agrawal, Ed., National Association of Corrosion Engineers, 1974, p 569-575... 

M.O. Speidel and M.V. Hyatt, Stress-Corrosion Cracking of High Strength Aluminum Alloys, Advances in Corrosion Science and Technology, M.G. Fontana and R.W. Staehle, Ed., Vol 2, Plenum Press, 1972, p 115-335... 

A.F. Beck and P R. Sperry, The Relationship between Structure and Susceptibility to Stress Corrosion in Aluminum-Magnesium Alloys, Fundamental Aspects of Stress Corrosion Cracking NACE I, R.W. Staehle, A.J. Forty, and D. Van Rooyan, Ed., National Association of Corrosion Engineers, 1969, p 513-529... 

M.O. Speidel, Current Understanding of Stress Corrosion Crack Growth in Aluminum Alloys, The Theory of Stress Corrosion Cracking in Alloys, S.C. Scully, Ed., NATO Scientific Affairs Division, Brussels, 1971, p 289-354... 

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