K

Figure 1.10. Stress corrosion time to failure, upon loading to initial K-level

-time to failure

Figure 1.11. Stress corrosion cracking

Iscc

-time to failure

Figure 1.11. Stress corrosion cracking

Figure 1.12. Relation between stress and crack length for stress corrosion to occur

The stress corrosion cracking threshold, Klscc. and the rate of crack growth depends upon the material and the environmental conditions. From figure 1.12 it follows that a component with a certain si/e of crack loaded to a stress a. such that as/na = Klc. fails on initial loading. Components loaded to K values at or above (shaded area) will show crack growth to failure. Although fracture mechanics concepts can be applied to stress corrosion cracking, the predictive power of these concepts is still very limited. Therefore the problem of stress corrosion cracking receives only limited attention in this volume.

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