- Higher cross section, and higher length jobs can be forged.
- Dies are flat mostly, so no die-sinking is needed. Thus, die cost is low.
- High rate of deformation at impact blow or high pressure.
- Fibrous structure is obtained. Uniform properties than rolled product.
- High strength, good ductility and good fatigue strength is obtained.
- Refinement of coarse grain and structure of ingot.
- Flaws, e.g., slag inclusions, porosity, etc., gets welded due to heavy working.
Tuesday, 18 March 2014
Advantages of Open Die Forging
Difference between Hot Working and Cold Working
HOT WORKING
- It is carried out above re-crystallization temperature.
- Refined and equiaxed structure is obtained.
- Surface finish is not good as Cold Working because of oxidation and decarburisation.
- Blow holes , porosity get welded during hot working.
- Probability of cracking is negligible.
- Diffusion occurs due to high temperature.
- It increases ductility and toughness.
- Dimensional tolerance is high.
- Oxidation and Decarburisation may occur.
- High loss of metal due to scaling.
- Isotropic properties.
- Less power is required.
- Severe embrittlement of reactive metals unless protected by protective atmospheres.
COLD WORKING
- It is carried out below re-crystallization temperature.
- Distorted grain structure is obtained.
- Surface finish is good.
- No chance of welding the blow holes and porosity.
- Probability of cracking is high.
- Diffusion does not occur due to low temperature.
- It increases strength.
- Dimensional tolerance is low.
- Oxidation and Decarburisation does not occur.
- Insignificant loss of metal.
- An-isotropic properties.
- More power is needed.
- No embrittlement.
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