Aluminum forgings can easily produce various defects during the forging process, including external and internal defects, artificially caused defects, and defects such as oxidation skin that may occur after heating. Today, we will popularize some common abnormalities in the manufacturing process of forgings.
The common defects of forgings can be divided into three aspects: internal, external, and performance. The internal defects of forgings can be further divided into two categories: low magnification defects and microscopic defects. The former includes internal cracks, shrinkage, porosity, white spots, disordered forging flow patterns, segregation, coarse grains, stone like fractures, and non-metallic inclusions; The latter, such as decarburization, carburization, banded structure, residual casting structure, and carbide segregation level, do not meet the requirements.
The most obvious manifestation of external defects is that after the forging is heated in the heating furnace and comes into contact with air, it will produce an oxidation reaction, resulting in a dense layer of oxide skin on the surface of the forging. The oxide skin here is the furnace generated oxide skin, which is relatively strong. If it is not removed during forging, it will cause defects on the surface of the forging, affecting the quality of the forging. Here, we suggest adding an oxide skin cleaning machine equipment before forging, Solving problems at the source is more effective.
Defects reflected in performance, such as unqualified room temperature strength, plasticity, toughness, or fatigue performance; Or the high-temperature instantaneous strength, persistent strength, persistent plasticity, and creep strength do not meet the requirements. The performance defects can only be determined with certainty after conducting performance tests.