How Foundries Perform Welding Of Cast Iron Castings?

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Foundries of CI Castings

• - By Rainbow
  Technocast Pvt. Ltd.

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Foundries of CI Castings

• Inroduction
• How Foundries Perform Welding Of Cast Iron
  Castings?
• Images of Cast Iron Castings
• Welding Techniques With Preheat
• Welding Techniques Without Preheat
• Conslusion
• Contacts
• Blogs and Articles

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Introduction

• Engineers may find the job of welding bit tricky,
  yet they do it all with perfection under harsh
  environment. In most cases, welding process of
  cast iron involves casting repairs. These repairs
  may be done inside the foundry that is producing
  various cast iron castings, or may be done when
  engineers determine them after machining process.
  Defected cast iron components can be repaired
  with welding technique. Broken cast iron
  components are rare and fixed by welding process.
  

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How Foundries Perform Welding Of Cast Iron
Castings?

• Manufacturers of castings use various range of
  cast iron and out of them, gray iron is their
  most preferred material to cast and shape. We are
  now going to discuss about a fact file of cast
  iron that helps us in understanding the
  challenges of welding.
• (1) Cast iron usually has 2-4 carbon content
  (this is about 10 times more than steel).
• (2) Due to presence of more carbon content, it
  form graphite flakes.
• (3) This graphite offers gray cast iron its
  characteristics looks when fractured.
• (4) When manufacturers form castings, molten cast
  iron is poured inside a mold cavity and allowed
  to set and slowly cool down.
• (5) With such slowly cooling technique, foundries
  can achieve crack-free or defect-less castings.
  It is necessary to keep the casting at cool place
  during or after welding process.

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Images of Cast Iron Castings
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Welding Techniques With Preheat

• Performing preheating process for cast iron parts
  prior welding will slow down the cooling rate of
  the weld and its surrounded region. As per
  experts, one should heat the entire casting and
  preheat temperature should be range from 500 F
  to 1200 F. Overheating will make the temperature
  critical for casting part. It is important to
  preheat the part uniformly and slowly to reduce
  cracking tendencies.

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Welding Techniques Without Preheat

• The size and other circumstances influence
  engineers to repair castings with welding by
  eliminating preheat process. For this, they keep
  the part cool, but not cold. The casting
  temperature raised to 100F and if the part is
  located on an engine, engineers me run it for a
  few minutes to attain this range of temperature.
  Heat the casting up to the temperature at which
  you can place your hand on it.
• After welding, peening is necessary and you
  should not raise the cooling rate with compressed
  air or water.

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Conclusion

• This is how cast iron castings foundries perform
  welding process. After Peening, they seal the
  cracks and give the perfect finish to the
  component.

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Contacts
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Blogs and Articles
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Social Contacts
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