Preparation of Non-corrosive Sample for High Temperature Laser Confocal Dynamic Observation

When the metallographic samples prepared by traditional metallographic sample preparation methods were observed in high temperature laser confocal microscope, the image will blacken locally due to the uneven corrosion of the phase interface. Taking GCr15 steel as an example, the metallographic sample suitable for high temperature laser confocal microscope observation was prepared by a new method. The results show that the pearlite in the original structure of GCr15 steel can be observed clearly under the high temperature laser confocal microscope when GCr15 steel was polished with 3 μm polishing solution for 20 min+1 μm polishing solution for 20 min+50% (mass fraction) silica sol for 20 min. Scanning electron microscope showed that the phase interface was continuous and there was no corrosion product. The metallographic sample preparation method is suitable for materials composed of two or more kinds of hard and soft phases.