Investigation of creep crack growth in heat-resistant tube steels

Results of an investigation are presented of creep crack growth in tube steels using 10 MoV 6 3 and 10 CrMo 9 10. Particular attention is paid to the load parameter C*. The current knowledge in the fields of empirical load parameter choice, specific materials behavior, continuum mechanics, and creep crack growth models is reviewed. The creep crack growth in steady state is qualitatively described. A prediction of the crack growth and hence of the lifetime on the basis of conservative assumptions is explained. A comparative life time estimate is proposed. The parameters which influence the creep crack growth are discussed. The creep crack growth micromechanism is explained too. (orig./MM)