Magnetic Particle Inspection Level 2 Practice Exam

Which one of the following is not a discontinuity common to forged products?

1. Laps

2. Shrinkage

3. Bursts

4. Flakes

The correct answer is: Shrinkage

Shrinkage is not a discontinuity commonly associated with forged products. In forging, the metal is subjected to high temperatures and pressures, which usually alleviates the formation of shrinkage cavities that can occur in processes like casting. The solidification of molten metal in casting can lead to shrinkage as the material cools and contracts, resulting in discontinuities. On the other hand, the forging process effectively compresses the material, minimizing voids and reducing the likelihood of shrinkage defects. In contrast, laps, bursts, and flakes are all potential defects that can occur during the forging process. Laps can arise from improper metal flow, resulting in thin layers that fold over themselves. Bursts are caused by excessive internal pressure during forging, leading to separation or rupture of the material. Flakes are often the result of improper material properties or excessive work hardening, leading to delaminations. Understanding these distinctions is crucial for identifying the types of discontinuities associated with various manufacturing processes.