In-service creep of materials for steam lines of thermal power plants and extension of their life

摘要

An analysis of 200,000 h of laboratory creep data for chromium-nickel-molybdenum-niobium steel tested at service loads and temperatures demonstrated a multistage creep nature, a transient stage of long duration (up to 20,000-25,000 h), an extended accelerated creep stage as compared to the duration of the steady-state one, and the existence of an avalanche creep stage. The relationships and their alternating sequences common to laboratory tests and service of materials in the structural elements of thermal power plants show that the creep data can be used to predict the service life of these materials.