Inspection of Castings

 Inspection  of Castings

In this blog, we will learn different way to inspect and testd to check the quality and defects in casting

There are two types of inspection in Casting
1. Destructive Inspection: In this casting, the workpiece is destroyed to check it various mechanical properties, chemical composition, defects in casting.
2. No Destructive Casting: This one is used to check the defects in the casting without damaging or destroying the workpiece. Here are some methods used in Non Destructive casting
  • Dimensional Inspection : In this after casting is done standard tool are used to check the dimensions of the casting workpiece. Various tools like vernier calliper, Go - NoGo gauge, template gauge are used to do this inspection.

  • Visual Inspection: In this, a person simply looks at the workpiece and check for the surface defects, cracks,misrun , wrapping etc.This is most common that is used in inspection.

  • Pressure Testing: This kind of testing is done to check the leakage or impermeability of metal.Casting product like tubes , cylinder go into this kind of testing to see is there any leakage somwhere. Normally a solution of soap and water is used if the bubble arises anywhere on workpiece it means leakage is there.

  • Radio - graphical Testing : This kind of testing is done to check cracks , internal voids, cavities etc. This testing is normally done by X-rays and γ rays (these rays can penetrate deep into the workpiece)
    X- ray are used for casting thickness 50mm to 180mm
    γ rays are used for heavy walled casting.Note : γ  rays can penetrate very deep as compare to X- rays

  • Magnetic Testing: This testing is done to check cracks slightly below the surface of the casting. This kind of testing can detect small crack that Radio - graphical testing can't detect sometimes (Only for ferro-magnetic materials).

  • Eddy Current Inspection: In this method high current frequency is passed through the workpeice that induced magnetic field. If there is any crack or leakage in the material magnetic field magnitude changes and detect by the instrument .
    (can use ferro-magnetic as well as some non-ferromagnetic process)

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