ETCHING SOLUTION AND ETCHING METHOD FOR HIGH-CHROMIUM STEEL, REPLICA SAMPLING METHOD AND CREEP DAMAGE ASSESSMENT METHOD

摘要

PPROBLEM TO BE SOLVED: To provide an etching solution that can be applied to high-chromium steel so as to distinguish and expose various microstructures in a metal structure, and a method which is non-destructive test and can evaluate creep damage of the high-chromium steel without using any expensive electron microscope. PSOLUTION: The etching solution is prepared by dissolving, in 6 mol water: 2.510SP-2/SPto 1.210SP-1/SPmol of sodium thiosulfate; 9.210SP-3/SPto 1.410SP-1/SPmol of potassium pyrosulfite and/or sodium pyrosulfite; 2.610SP-4/SPto 1.510SP-2/SPmol of citric acid; and 8.510SP-2/SPto 3.510SP-1/SPmol of ethanol. The metal microstructure exposed through an etching treatment using the etching solution is observed under an optical or laser microscope to determine a subgrain size, and the creep damage is derived from the subgrain size. PCOPYRIGHT: (C)2011,JPO&INPIT