Common defects of profiles

After rolling, extrusion forging, the microstructure properties of the ingot are improved significantly. Generally, the more complete the deformation is, the less residual casting defects are, the greater the improvement range of material quality is. However, in the process of rolling, extrusion forging, new defects may occur

1. Scratch (scratch)

In the rolling process, due to various unexpected reasons, the surface of the metal is scratched with a depth of 0.2 to 0.5 mm.

2. Folding

During rolling, the metal on the surface of the rolled product is turned into the inner layer elongated. Due to the oxide in the crease, it can be forged, resulting in folding.

3. Hair crack

The steel ingot subcutaneous bubbles are flattened elongated to form hairy cracks with a depth of about 0.5 to 1.5 mm. It is easy to produce this kind of defect in high carbon steel alloy steel.

4. Scarring

When pouring, the molten steel splashes solidifies on the surface of ingot. In the process of rolling, it is smashed into thin film adheres to the surface of rolled products. Its thickness is about 1.5 mm.

5. Carbide segregation

6. White dot

7. Streamline of nonmetallic inclusion

8. Coarse grained ring