Which of the following discontinuities is typically caused by the rolling process?

The discontinuity that is typically caused by the rolling process is laminations. Laminations occur when there are layers within the material that have not been properly bonded together, and they can be a result of factors such as inadequate heating or insufficient pressure during the rolling process.

In manufacturing processes like rolling, the metal is subjected to high pressure and temperature, which can sometimes lead to the formation of these internal layers if the material is not uniform or if impurities are present. This type of discontinuity can affect the mechanical properties of the material, leading to reduced strength and performance.

Understanding laminations is crucial in magnetic particle testing because they can negatively impact the integrity of the material and may not be detectable with certain inspection methods unless specifically targeted. Recognizing and differentiating laminations from other types of discontinuities, such as cracks or laps, is essential for accurate evaluation and quality control in material inspection.