ULTRASONIC TESTING OF HEAVY FORGING

The welding machine and ultrasonic testing of heavy forging go hand in hand for the better quality in welding and forging by Cruxweld equipment in the market. The complex shapes, the surface curvatures, and large dynamically stressed forgings may not allow good contact or coupling. The angles and surfaces of large and varied origins may prevent back wall echoes with probes of simple or complex anisotropic in grain structures different sizes are in different directions.
Techniques:
The process of searching the defects in forgings one must have a set of information which is usually written on an instruction sheet.
.The test component and area of material to be tested.
.The set of action to be taken once the defect is detected.
. The purpose of the test to detect the defect and acceptance criteria for the material.
. The requirement of the equipment.
. The method and level of sensitivity to use in testing.
. The method of testing.

  The instruction sheet would also have sections giving every detail and possible safety measures and cleaning of the test area afterward. It would also have the company name, a unique technical reference number, originators name and signature by the authorized person.

The Test Area:
The test may involve testing of the whole, or a component, or just a part all these must be specified in the required sheet.
Actions to be taken:
The reporting of the defect may lead to accepting or rejecting the material. The defect found to be noted in details as a diagram and complete description of the defect as the site of the defect, its position as lateral, longitudinal, etc. In a nutshell, the defect to be reported in every possible minute details as this may lead on to acceptance and or rejection of the material.
Purpose of the Test:
This will tell us the accept/reject criteria for the particular defects. The size and type of defects to report which make the tested component rejectable.
Equipment and Testing:
In an ultrasonic examination, we use high-frequency sound waves which when transmitted into forged steel part to detect discontinuities or locate changes in material characteristics. The sound is introduced into steel forging part being examined and reflections from internal imperfections area of acoustic impedance or varying geometrical surfaces are returned to a receiver.

Scanning Methods: The methods o scanning should be laid as per the national and international standard in a sheet. The scanning method should be listed step by step as in the following manners.

1. Prepare the material surface by removing any loose scale, dirt, rust or any other debris and visually inspect or damage or surface defects.
2. The screen on flaw detector to be calibrated using a probe and calibration block or a range of 0 to 200 mm.
3. Apply the couplant to the test area after setting the sensitivity.
4. Scan the designated area with a probe overlap between the scan of at least 20% of the probe diameter and at a maximum probe movement rate of 150mm/sec.
5. When we find defects meeting the criteria in the purpose of the test section, record the relevant defect data as in the action to be taken the section.
6. Now it is time to prepare a neat and concise report giving every possible detail of component identification, test area, equipment used, sensitivity method and settings. Make a drawing with defects details recorded and duly signed by the welding inspector and company seal on it.
Post-test Procedure:
This will involve cleaning any remaining couplant from the test area and covering the surface with protective coatings according to clients requirements

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