Stress corrosion cracking testing

Figure 4-442. Specimen extension as a function of time during constant-load stress-corrosion cracking test. (From Ref. [183].)...

The oxygen concentration of the solution, as in many instances of corrosion, can also be critical in stress-corrosion cracking tests. Instances are available in the literature that show very markedly different test results according to the oxygen concentration in systems as widely different as austenitic steels immersed in chloride-containing phosphate-treated boiler water and aluminium alloys immersed in 3% NaCl. 

Method for performing a stress-corrosion cracking test of low copper containing Al-Zn-Mg alloys in boiling 6% sodium chloride solution... 

Comparison of the results from stress corrosion cracking tests.123... 

C.D. Kim and B.E. Wilde, A Review of the Constant Strain-Rate Stress Corrosion Cracking Test, Stress Corrosion Cracking—The Slow Strain Rate Test, STP 665, G.M. Uganisky and J.H. Payer, Ed., ASTM, 1979, p 97-112... 

Wei, R. P., Novak, S. R., and Williams, D. P., Some Important Considerations in the Development of Stress Corrosion Cracking Test Methods, AGARD Conf. Proc. No. 98, Specialists Meeting on Stress Corrosion Testing Methods, 1971, Materials Research and Standards, ASTM, 12,9 (1972), 25. 

J. Sedriks, Stress corrosion cracking test methods, NACE, Houston, 1990. 

Definition and Characteristics of Stress Corrosion Cracking Testing Methods... 

J. Sedtiks, Making and using precracked cantilever beam specimens, in Stress Corrosion Cracking Test Methods, National Association of Corrosion Engineers (NACE), Houston, TX, 1990, pp. 37 5. 

C. D. Kim, B.E. Wilde, A review of the constant strain-rate stress corrosion cracking test, in G. 

Figure llA Intergranular fracture of Al-4% Cu alloy subjected to stress corrosion cracking test in NaCl. 

F ure 11.6 Real and nominal stress versus time in stress corrosion cracking tests at constant load and constant deformation. 

Figure 11.12 Variation of crack propagation rate with stress intensity factor during a stress corrosion cracking test (schematic).

F ure 11.14 Pre-cracked probe shapes for stress corrosion cracking tests (a) compact tension specimen (CT) and (b) double cantilever beam specimen (DCB). 

Figure 11.35 Time to failure for different austenitic stainless steels subjected to constant-load stress corrosion cracking testing in boiling magnesium chloride solution [15].

G 36 Practice for Performing Stress-Corrosion Cracking Tests in a Boiling Magnesium Chloride Solution... 

See ASTM G 103, Test Method for Performing a Stress-Corrosion Cracking Test of Low Copper Containing Al-Zn-Mg Alloys in Boiling 6 % Sodium Chloride Solution. 

Stress Corrosion Cracking Testing in Mattsson s Solution... 

ASTM G 37 (Practice for Use of Mattsson s Solution of pH 7.2 to Evaluate the Stress Corrosion Cracking Susceptibility of Copper-Zinc AUoys) is an accelerated stress corrosion cracking test environment for brasses (copper-zinc alloys). The use of this test environment is not recommended for other copper alloys since the results may be erroneous, providing completely misleading rankings. This is particularly true of alloys containing aluminum or nickel as deliberate alloying additions. 

G 44 can be used for both stressed and unstressed specimens. Historically, it has been used for stress corrosion cracking testing, but often is used for other forms of corrosion, such as uniform, pitting, intergranular, and galvanic. It uses a 1-h cycle that includes a 10-min period in a aqueous solution of 3.5 % sodium chloride (NaCl) followed by a 50-min period out of the solution, during which the specimens are allowed to dry. This 1-h cycle is continued 24 h/day for the total number of days for the particular alloy being tested. 

DIN 50916, Stress Corrosion Cracking Test Using Ammonia, Cologne, Germany, September 1985. 

The standard methods used include ASTM [27], ANS, NACE, and numerous other methods [26,28,29], Many important methods are not yet standardized such as the stress corrosion cracking test method [30], and autoclave testing methods [37,32] Table 3 gives a list of the more common test methods tmd the tested corrosion parameters. 

Therefore, a new stress corrosion cracking test method was developed (Creviced Bent Beam CBB test), which considers the crevice effect as well as factors B, C and D above. Bend test specimens with an artificial crevice made from graphite wool (more sensitive than those made from PETE and especially metal-metal) were tested (both welded and non-welded but sensitised at 600 C/2 h) in high purity water with 0.2 pS/cm, oxygen saturated, chloride < 0.1 mg/1, pH S.8-6.2 at 250 C. For more than 20 steel specimens with different carbon contents (which are responsible for various susceptibilities to sensitisation) one obtains very clear conclusions from 20 specimens each of them showed stress corrosion cracking after only 24 hours, so long as the carbon content lied in the range 0.06-0045%. In the process cracks with... 

Table 8 Results of intergranular stress corrosion cracking tests with a silicon alloyed 18 8Ni...

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