6. Maintenance and damage counters

Throughout the previous paragraphs, we have discussed the impact on the life of parts. Over time, as a result of operating conditions or stresses caused by more or less rapid variations in power output, parts accumulate damage which, if not repaired or changed, can lead to failure. This is why manufacturers have defined inspection intervals, using various methods to accumulate damage.

According to § 2.4, the two types of damage are :

• creep caused by holding the material for hours at flame temperatures close to the maximum, which is counted in equivalent operating hours. An increase in local metal temperature of around ten degrees reduces the material's creep resistance to 50-70% of its initial value. Peak operation influences metal temperature (20°C overfiring as defined at