SUMMARY

Hydrogen attack is a material degradation process that occurs at elevated temperatures in hydrogen-rich environments, such as found in petrochemical installations. Weldments in components such as reactor vessels are particularly susceptible to hydrogen attack. This paper discusses a multi-scale micromechanics modelling approach in which the chemico-mechanical damage processes at sub-micron scale are coupled to the macroscopic behaviour through a series of size-scale transitions. A simulation of hydrogen attack in a welded reactor serves as an illustration of the approach. Copyright? 2001 John Wiley & Sons, Ltd. KEY WORDS: micromechanics; fracture; creep; hydroge