抄録
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 being different to the exposed temperature. But the reference temper colors are shown only by the designated colors without photographic examples in the Code. 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. However, the details of metallurgical analysis are not available in the Code. It is desirable for these points to be improved for more user friendliness. The Japanese Fitness-For-Service Committee organized by the Petroleum Association of Japan and the Japan Petrochemical Industry Association is working on the localization of fitness-for-service standard harmonizing with API⁄ASME. The Committee has prepared supplemental references for the photographic temper color examples and the guideline of metallurgical analysis, and proposes incorporating them into the Code. This paper presents the contents of those references prepared by the Committee. The temper color reference shows several photographic examples of different exposed temperature, elapsed time and cooling rates for carbon steel and stainless steel. The metallurgical analysis guide describes typical degradations in mechanical properties and appearances in microstructure observed in the materials exposed to fire, evaluation criteria, procedure for replica preparation, personnel qualification and so on.
