首页>
外国专利>
METHOD OF SEPARATELY VISUALIZING AUSTENITE PHASE, MARTENSITE PHASE AND BAINITIC-FERRITE MATRIX IN BAINITIC STEEL AND BAINITIC STEEL SPECIMEN FOR MICROSTRUCTURE OBSERVATION
METHOD OF SEPARATELY VISUALIZING AUSTENITE PHASE, MARTENSITE PHASE AND BAINITIC-FERRITE MATRIX IN BAINITIC STEEL AND BAINITIC STEEL SPECIMEN FOR MICROSTRUCTURE OBSERVATION
A method of separately visualizing an austenite phase, a martensite phase and a bainitic-ferrite matrix in a bainitic steel capable of identifying the austenite and martensite phases in the bainitic steel at the nanoscale is provided. The method includes the steps of: a) electro-polishing a surface of a specimen of a multiphase steel in an electrolyte solution containing a corrosive acid and an organic solvent to form a native oxide layer on the surface of the specimen, b) after completion of the electro-polishing, continuously retaining the specimen in the electrolyte solution to form first and second corrosion product layers selectively on domains of the native oxide layer covering martensite and austenite phases, respectively, and c) subjecting the surface of the specimen to scanning electron microscopy observation by means of a backscattered electron detector and providing a contrast between the first and second corrosion product layers and remaining surface to visualize the austenite phase as a darkest area, the bainitic-ferrite matrix as a brightest area, and the martensite phase as an intermediate brightness area; wherein the step c) is performed under a condition that a landing energy of the primary electrons is 3 keV or less.
展开▼
