Forging quality inspection items are as follows:

(1) Geometric Shape and Dimensions

General forging dimensions are measured using steel rulers, calipers, and templates, etc. Complex-shaped die forgings can be inspected using the marking method.

(2) Surface Quality

Surface cracks, indentation, or folding defects on forgings are generally visible to the naked eye. Sometimes, cracks may be very small, and the depth of the fold may be uncertain; in such cases, re-cleaning and observation may be necessary. In case of necessity, ultrasonic testing can be used to inspect for defects.

(3) Internal Structure

Internal defects such as cracks, inclusions, and porosity in forgings can be inspected visually or with a magnifying glass between 10 to 30 times on the forging fracture surface's macrostructure. The commonly used method during production is acid etching inspection, where a sample is cut from the part of the forging to be inspected and immersed in an acidic solution, which clearly reveals the defects in the macrostructure of the fracture, such as forging flow lines, cracks, and inclusions.