<img alt="" src="https://secure.hims1nice.com/150891.png" style="display:none;">

Green Sand Metalcasting Foundry News

20 Green Sand Casting Defects and Their Suggested Remedies

Posted by Hill and Griffith Company on Sep 24, 2019 2:30:50 PM

Originally published January 2017 by Mechanical Engineering

Probable causes and suggested remedies of various casting defects such as blow holes, shrinkage, porosity, misruns, hot tears, mental penetration, cold shuts, cuts and washes, inclusions, fusion, drops, shot metal, shift, crushes, rat-tails, swells, hard spot, run out, fins and fash, spongings and warpage are given in the below table.

Casting Defects

Photo credit: Green Mechanic

S.no
Name of Casting Defect
Probable Causes
Suggested Remedies
1 Blow holes
  1. Excessive moisture content in molding sand.
  2. Rust and moisture on chills
  3. Cores not sufficiently baked.
  4. Excessive use of organic binders.
  5. Molds not adequately vented.
  6. Molds not adequately vented.
  7. Molds rammed very hard.
  1. Control of moisture content.
  2. Use of rust free chills, chaplet and clean inserts.
  3. Bake cores properly.
  4. Ram the mold less hard.
  5. Provide adequate venting in mold and cores.
2 Shrinkage
  1. Faulty gating and risering system.
  2. Improper chilling.
  1. Ensure proper directional solidification by modifying gating, risering and chilling.
3 Porosity
  1. High pouring temperatures.
  2. Gas dissolved in metal charge.
  3. Less flux used.
  4. Molten metal not properly degassed.
  5. Slow solidification of casting.
  6. High moisture and low permeability.
  1. Regulate pouring temperature.
  2. Control metal composition.
  3. Increase flux proportions.
  4. Ensure effective degassing.
  5. Modify gating and risering.
  6. Reduce moisture and increase the permeability of mold.
4 Misruns
  1. Lack of fluidity ill molten metal.
  2. Faulty design.
  3. Faulty gating.
  1. Adjust proper pouring temperature.
  2. Modify design.
  3. Modify gating system.
5 Hot Tears
  1. Lack of collapsibility of core.
  2. Lack of collapsibility of mold.
  3. Faulty design.
  4. Hard ramming of mold.
  1. Improves collapsibility of core and mold.
  2. Modify casting design.
6 Mental penetration
  1. Large grain size and used.
  2. Soft ramming of mold.
  3. Molding sand or core has low strength.
  1. Use sand having finer grain size.
  2. Provide hard ramming.
  3. Suitably adjust pouring temperature.
7 Cold shuts
  1. Lack of fluidity in molten metal.
  2. Faulty design.
  3. Faulty gating.
  1. Adjust proper pouring metal.
  2. Modify design.
  3. Modify gating system.
8 Cuts and washes
  1. Low strength of mold and core.
  2. Lack of binders in facing and core stand.
  3. Faulty gating.
  1. Improve mold and core strength.
  2. Add more binders to facing and core sand.
  3. Improve gating.
9 Inclusions
  1. Faulty gating.
  2. Faulty pouring.
  3. Inferior molding or core sand.
  4. Soft ramming of mold.
  5. Rough handling of mold and core.
  1. Modify gating system.
  2. Improve pouring to minimize turbulence.
  3. Use of superior sand of good strength.
    Provide hard, ramming.
10 Fusion
  1. Low refractoriness in molding sand.
  2. Faulty gating.
  3. Too high pouring temperature of the metal.
  4. Pouring facing sand.
  1. Improve refractoriness of sand.
  2. Modify gating system.
  3. Use Lower pouring temperature.
  4. Improve the quality of facing sand.

Read more about the next 10 Green Sand Casting defects and their remedies at Mechanical Engineer.


More News from Mechanical Engineer

A Quick Guide to Investment Casting

Casting Process: Advantages and Limitations



Hill and Griffith Customer Service

The Hill and Griffith Company's green sand metal casting foundry supplies help achieve the EPA's M.A.C.T. standards and reduce Benzene emissions. Our variety of environmentally sound release agents, coatings, partings, lubricants, core oils and specialty products will help you meet your metal casting's needs. We're known for our hands-on approach. Let us visit your plant and recommend products that suit your needs.

Hill and Griffith Samples

Product Samples

We are pleased to provide samples in quantities large enough to allow you to "try before you buy."
Contact Us »

 

Hill and Griffith Customer Service

Technical Services & Support

On-site casting defect investigations, product testing, machine start-ups and much more. Also, lab facilities are available to provide testing upon request.
Contact Us »

 

Bulletins and Technical Papers for Metal Casting Products

Tags: Green Sand Casting Products, Green Sand Foundry Supply, Foundry Supply, Green Sand Release Agents, Foundry Supplies, Mechanical Engineer

Subscribe to the Green Sand Metal Casting News

Recent Metalcasting News

Follow Me

Metalcasting News Categories

see all