Weld Evaluation Of Camshafts Using Ultrasonic Testing

Generally, ultrasonic testing (UT) is used to figure out the quality of brazed joints. With the help of this unique process, evaluating brazing quality becomes simple. It uses a focused transducer, and ultrasonic waves along the radius of the shaft are focused on the brazed joint. By monitoring the amplitude of the echoes returning from the joint position, one can evaluate the brazing quality easily.

When the echo becomes weak, it indicates a strong bond where most of the ultrasonic waves travel through the joint. On the other hand, a strong echo means that there is no mechanical bonding, causing the ultrasonic waves to bounce back at the interface. A reference sample with a known unbonded area can be used to set the ultrasonic machine sensitivity and evaluate the amount or percentage of any flaw in the part.

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Camshafts

Camshafts are typically manufactured by machining cast iron, forged steel or billets down to the desired shape. Some manufacturers have started to produce camshafts by joining cams to shafts with a brazed joint. Due to the force being potentially applied to the brazed joint, quality control is required to ensure brazing quality and that a sufficient percentage of cam is solidly brazed to the shaft. Ultrasonic testing must be conducted only through experts who provide certified non destructive testing in Melbourne.

Camshaft geometry

A camshaft is basically a shaft with cams distributed along its length. Cams can come in different shapes with one common characteristic: there is at least one protuberance found along the circumference, resulting in an irregular shape. A common model is a cam with a nose (lobe), where the brazed joint is not parallel to the outer surface. In such a situation, there is little to no probability of recording an echo from the joint; this is what will be referred to as the uninspectable area of a cam.

Brazed joint evaluation

It is not always necessary to inspect each individual part of the camshaft to control the quality of a production. A statistical analysis can be performed on sampled parts taken from the production line. The same logic applies to the uninspectable area of the cams; a statistical analysis can still be performed by monitoring the percentage of good brazing within the inspectable portion of the cams. When using ultrasounds to monitor the brazed joint quality, the evaluation must be normalized to ratio of inspectable area.

As ultrasonic testing is sensitive to both surface and sub-surface discontinuities, be sure to hire the certified personnel to figure out the flaws properly and end on a positive note.

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The Working Processes Of A Good Welding Inspector

Welding InspectionA typical welding inspector is entrusted with the task of overseeing each and every activity as well as duty of a welding staff so as to ensure that all things are in ideal working manner. The job of the professional is making sure that welders conduct their tasks within the fixed deadline and quality specifications. It is also important for him or her to possess advanced knowledge about welding processes and procedures in order to be capable of providing guidance in problematic scenarios.

A good welding inspector is also expected to visually assess the welded products in order to check for room to improve or eliminate deformities. They can even utilise stress equipment for putting stress on weld joints. They are responsible for collecting records of readings from tests for future reference. They primarily work in the field of manufacturing processes and building construction.

Let’s take a quick look at the the different duties performed by professionals of welding inspection in Melbourne:

Welding Inspection

  • Interpretation of purpose as well as requirements of the various standards, codes and specifications.
  • Making sure that a specific process is available, approved and employed in the production.
  • Verifying the availability of enough legitimate welder approvals, and also making sure that only the approved ones are utilised in production.
  • Checking the parent material against markings and documentation.
  • Inspecting the correctness of different welding consumables like gases, fluxes, filler wires, electrodes, consumable inserts, etc.
  • Inspecting that the fit-up, weld preparations and dimensions are according to the specifications.
  • Verifying that the required preheat complies with the particular procedure.
    Assistance & agreement along with preparation of ITPs or Inspection & Test Plans.
  • Surveillance at the time of welding for ensuring compliance with required procedures like preheat, post heat and interpass temperature control requisites.
  • Inspecting to ensure conduction of post weld heat treatment as per specification requirements.
  • Dimensional check and visual inspection of the completed weld against specification drawings and requirements.
  • Utilising various methods of non destructive testing like magnetic particle, ultrasonic inspection, radiography or liquid penetrant to study their results on a specific welding work.
  • Evaluating and preparing inspection reports for a client or employer.
  • Maintaining each and every record of all inspections that they have carried out.

So, basically, these are the things that comprise the regular working processes of a certified welding inspector in Melbourne or anywhere else in Australia. They play a very important role in ensuring the quality & safety of different manufactured products.