Identify the type of casting defect indicated in the given diagram.

Question

Question

This question was previously asked in

DFCCIL Executive Mechanical 28 Sept 2021 Paper (Shift 1)

Answer 1

Explanation:

Casting defects

Cold Shut

A cold shut is caused when two streams while meeting in the mould cavity, do not fuse together properly thus forming a discontinuity in the casting.
When the molten metal is poured into the mould cavity through a more-than-one gate, multiple liquid fronts will have to flow together and become one solid.

Misrun:

When the molten metal solidifies before completely filling the mold cavity and leaves a space in the mold called as misrun.
Cause:
- Low fluidity of the molten metal.
- Low temperature of the molten metal which decreases its fluidity.
- Too thin section and improper gating system.

Shrinkage Cavities:

It is a void on the surface of the casting caused mainly due to uncontrolled and haphazard solidification of the metal.
These are caused by the liquid shrinkage occurring during the solidification of the casting.
To compensate this, proper feeding of liquid metal is required and also proper casting design.
Shrinkage defects can be split into two different types:
- Open shrinkage defects
- Closed shrinkage defects