Preparation and surface morphology observation of a new type of valve alloy NCF3015 metallographic specimen

A new method for preparing metallographic specimens of NCF3015 gas valve alloy with iron－based aging strengthening after aging treatment was introduced. The specimens were ground and polished using a pre－mill, and electrolytic corrosion was carried out using a 10% (volume fraction) oxalic acid solution. The surface morphology of specimen was observed using a stereomicroscope and an optical microscope. A solution was proposed to address the issues of scattered scratches, trailing edges and multiple planes on the surface of NCF3015 valve alloy specimens after aging treatment, resulting in a high－quality metallographic specimen with a smooth and scratch free surface.