Macrostructure

The inspection of macrostructure defects of metals is also called macro inspection. It is a method to inspect metal surface, fracture or macrostructure and defects with naked eye or magnifier no more than ten times. Macro inspection is an important and commonly used inspection method in the process of metal ingot, casting, forging, welding, rolling, heat treatment, etc. This test method is simple and rapid, and can reflect the morphology and distribution characteristics of microstructure and defects in the macro region of metal. So that people can correctly and comprehensively judge the quality of metal materials, so as to guide the scientific production and rational use of materials. It can also be used for further optical metallographic and electronic metallographic analysis.            Macro inspection includes macrostructure and defect inspection (including acid etching, sulfur printing, tower turning, nondestructive damage control, etc.) and fracture analysis.            The typical macro defects are segregation, porosity, shrinkage cavity, bubble, crack, low power inclusion, coarse crystal ring, etc.