Abstract
A guideline of fitness-for-service assessment to fire damage is introduced to API 579-1⁄ASME FFS-1 Code. Since the fire damage evaluation is based on the material degradation associated with heat exposure, the identification of heat exposure zone will be essential. The Code provides guidance to judge the heat exposure zone and one of useful information is temper colors of steels vary according to the exposed temperature. And also, further investigations may be carried out to test such mechanical properties as tensile strength, hardness, impact energy, ductility and so on for the damaged material. Interpretation of those test results should be endorsed by metallurgical analysis. In the 2016 edition, the temper color reference shows several photographic examples of different exposed temperature, elapsed time and cooling rates for carbon steel and stainless steel. And references are added to annex 11A, procedures for investigating cause and organization replica evaluation are added annex 11B. As a result, it was improved to make it easier to use.
