ESTIMATION METHOD USING CALIBRATION CURVE OF REMAINING LIFESPAN OF TUBING HAVING BAINITE STRUCTURE

摘要

The objective of the present invention is to estimate the remaining lifespan of tubing having a bainite structure. The present invention is an estimation method that uses a calibration curve of the remaining lifespan of cylindrical tubing having a bainite structure and that incurs creep failure as a result of heating and pressurization. A hollow sample (10) of the same material as the tubing is subjected to heat and pressure, the outer diameter is measured, and the outer diameter is measured a plurality of instances at predetermined times in order to create a calibration curve indicating the relationship between the expansion rate in the diametral direction of the sample (10) and the remaining lifespan of the sample (10). Afterwards, the outer diameter of the tubing is measured, and the remaining lifespan of the tubing is estimated on the basis of the aforementioned calibration curve and the expansion rate in the diametral direction of the tubing.