Classification of Discontinuities

Inclusions: Non-metallic impurities, such as sand, slag, oxides, and sulfides that are present in the original ingot. Rolling of raw material into billets or bar stock, these impurities form “stringers”, or lines. When rolled plate it form lamination.

These discontinuity is objectionable, when they occur in critical areas, on highly-stressed surfaces, or in unusual numbers.


Porosity: Gas bubbles being trapped in the material prior to solidification. Bubbles generally round or spherical in shape.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s