Page 307 - CITS - Welder - Trade Practical

WELDER - CITS

Job Sequence

• Seam welding can generate large amounts of heat
• Especially when making a liquid tight continuous weld.
• This heat is very visible at the actual weld joint.

• You stated that you are using cooling water as specified by the machine manufacturer at 20 l per minute.
• This may be adequate for the machine under normal operation.
• It does not mean that at the weld area the cooling is adequate.
• Heat can be a suspect to address.
• The machine produces good welds for 300 meters.

• Then cracks appear
• After stopping for a period of time the machine is cooled down.
• A restart produces good product for another 300 meters.
• If the hub cooling of the wheel cannot adequately cool the wheel to keep the wheel rim face at a steady heat
condition, the rim face heat will build up and gradually get hotter.
• The part will not cool as quickly and the process will change.
• Apparently, CRACKING results.

Note: Wear protective clothing.

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CITS : CG & M - Welder - Exercise 80