COLORED ETCHANT AND ETCHING METHOD CAPABLE OF IDENTIFYING RETAINED AUSTENITE FROM OTHER STRUCTURE

摘要

PROBLEM TO BE SOLVED: To provide a colored etchant and etching method using the same, capable of grasping volume fraction of retainedγin a bainite structure, shape and distribution state by etching with a corrosive liquid.SOLUTION: The colored etchant capable of identifying retained austenite from other structure is a solution which the total 2.4×10to 17.1×10mol of at least one of sodium pyrosulfite (NaSO) and potassium pyrosulfite (KSO) is dissolved in water (HO) of 1 mol, then 1.6×10to 11.8×10mol of picric acid OHCH(NO)is added.