Forgeable piece refers to a workpiece or blank obtained by forging and deforming a metal billet.
The quality inspection items for forgings are as follows:
(1) Geometric shape and size
The overall dimensions of general forgings are tested using measuring tools such as steel rulers, calipers, and templates; Die forgings with complex shapes can be accurately inspected using the marking method.
(2) Surface quality
If there are cracks, indentations, or folding defects on the surface of forgings, they can generally be detected with the naked eye. Sometimes the cracks are very small, and when the depth of the fold is unknown, it can be observed after cleaning the shovel; If necessary, flaw detection can be used for inspection.
(3) Internal organization
Whether there are cracks, inclusions, looseness and other defects inside the forging, the macroscopic structure on the forging section can be inspected with the naked eye or with a 10-30 times magnifying glass. The commonly used method in production is acid corrosion inspection, which involves cutting samples from the parts of forgings that need to be inspected and etching them with acid solution to clearly display the macroscopic defects on the cross-section, such as forging flow line distribution, cracks, and inclusions.
(4) Metallographic examination
The inspection method of observing the fracture microstructure of forgings using a metallographic microscope can examine items such as carbide distribution, grain size, and decarburization depth.
(5) Mechanical properties
The mechanical property inspection items mainly include hardness, tensile strength, and impact toughness. Sometimes, according to the design requirements of the parts, cold bending tests, fatigue tests, etc. can also be carried out.
The above quality inspection items are sometimes used separately based on design requirements and actual production conditions, sometimes inspected piece by piece, and sometimes sampled according to each batch of forgings. By quality inspection, the qualification of forgings can be evaluated. For forgings with defects, the causes should be analyzed and preventive measures should be proposed.