Controls whether CAESAR II uses corroded section modulus in stress calculations.
The B31.3 piping code reduces the section modulus for sustained or occasional stress calculations by the reduction in wall thickness due to corrosion. Using All Cases Corroded causes the software to use the corroded section modulus for the calculation of all stress types. This method is conservative, and probably more realistic because corrosion can significantly affect fatigue life or expansion.
When you clear All Cases Corroded, the software follows the piping code recommendations. That is, depending on the active piping code, some load cases consider corrosion, and some do not.
See Corrosion in The Effect of Configuration Settings on Piping Code Calculations.
When B31J is enabled (through Apply B31J SIFs and Flexibilities), the software ignores this configuration option. See Basis for SIF and Flexibility Calculations in B31J Methods.