ミニチュアクリープ試験によるボイラ水冷管の健全性評価

抄録

In order to ensure integrity of equipments working under high temperature, simple and convenient creep tests are required. Miniature Creep (MC) test is one of uniaxial creep tests using small size specimen. It can evaluate creep properties of thin or small parts, e.g., turbine blade and HAZ. In this study, using MC tests, authors examined creep characteristics of an aged boiler tube (STBA20) that had been used for nearly 60,000 hours. Creep life of virgin STBA20 material was estimated using Time-Temperature Parameter (TTP) methods, i.e., Larson-Millar and Manson-Hafard parameter methods. Then, there was little difference of creep life between aged and virgin materials, and it was also shown that aged boiler tube would be rarely damaged ; it has almost the same strength of virgin material.