How metal concentration can be avoided at Junction in casting?
Avoid concentration of metal at Junctions: Due to concentration of molten metal at the junction the central portion can’t solidify completely leaving shrinkage cavity at the centre. This can be avoided b two ways: A. By providing the core hole in the center.
What is sharp corner?
Adj. 1. sharp-cornered – having sharp corners. sharp-angled. angulate, angular – having angles or an angular shape.
Why do people have rounded edges?
Rounded corners are more effective for maps and diagrams because they allow our eyes to easily follow lines “as it suits better to the natural movement of the head and eyes respectively” [5]. Sharp corners throw your eyes off the path of the line so you end up experiencing abrupt pauses when the line changes direction.
Which type of precaution will you take to avoid corrosion of steel structure *?
HOT-DIP GALVANIZATION This corrosion prevention method involves dipping steel into molten zinc. The iron in the steel reacts with the zinc to create a tightly bonded alloy coating which serves as protection.
How does proper design prevent corrosion?
Here are a few key design rules that can be followed to help prevent corrosion:
- Adjust Wall Thickness.
- Ensure that there’s Adequate Drainage.
- Minimize Bi-Metallic Corrosion Cells.
- Avoid Differential Aeration Cells.
- Figure 1.
- Minimize Temperature Gradients.
- Minimize Stress Gradients.
- Separate Environments.
What is shrinkage cavity?
a void in an ingot or shaped metal casting, formed during the solidification of the molten metal as a result of shrinkage. Shrinkage cavities are usually located in the upper portion of an ingot or in those spaces within a casting where the molten metal is last to enter during pouring.
Why does shrinkage occur in casting?
Shrinkage casting defects and causes. Shrinkage occurs because metals are less dense as a liquid than a solid. A shrinkage cavity is a depression in a casting which occurs during the solidification process. Shrinkage porosity appears with angular edges, compared to the round surfaces of gas porosity.