METHOD FOR MEASURING SURFACE CRACK LENGTH OF HIGH- TEMPERATURE EQUIPMENT

• Main Author: KOYAMA TERUO
• Format: Patent
• Language: English
• Published: 23.01.2002
• Edition: 7
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

PROBLEM TO BE SOLVED: To provide a method for measuring a surface crack length of a high- temperature equipment whereby the surface crack length of a material used in the high-temperature equipment can be correctly measured without removing an oxide film even when the oxide film is thick. SOLUTION: In the method for measuring the length of the surface crack generated to the material used in the high-temperature equipment such as a boiler or the like, there are included a step (i) of measuring a crack length of the oxide film at a position of the material to be investigated; a step (ii) of measuring a thickness of the oxide film or estimating the thickness of the oxide film from an operating temperature and a time, and a step (iii) of converting the crack length of the above-measured oxide film to a crack length on a metal surface on the basis of a previously obtained relation for every thickness of the oxide film between the crack length of the oxide film and the crack length of the metal surface.