scope:

This AD 2000-Merkblatt contains criteria for handling creep-stressed steels. It shall be used when a creep-induced change in the material characteristics is to be expected as a result of the effect of temperature. The following lower limit temperatures apply here:

- approximately 380 °C for alloyed steels, 

- approximately 440 °C for low-alloy steels, 

- approximately 525 °C for high-alloy steels (austenitic, ferritic, martensitic steels). 

The exact limit temperatures shall be determined on the basis of the relevant harmonized material standard. The use of other materials is possible but the suitability has to be established in the form of an appraisal according to 4.2 of Annex I of Directive 97/23/EC from a notified body for each case. 

This AD 2000-Merkblatt applies only in conjunction with the AD 2000-Merkblätter of the B Series. For the AD 2000- Merkblätter S 3 and S 4, a special stress assessment concept is required.