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Quality control of forgings. Measuring cracks depth with electrical potential 281M Crack Depth Meter

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making_forgings.jpgEach stage of forgings manufacturing demands quality control. It is crucial. The main aims of monitoring consist of detecting external and internal defects and evaluating potential risks they bring for the strength properties of finished products.

This article will focus on a widespread defect in forgings, which is surface cracks. We will also reveal some details about measuring them using the electrical potential Crack Depth Meter 281M.

Methods of making forgings

Forging is a metal blank, which is used in rolling or in the manufacturing of standard products.

These blanks are products of hot forging. During the process, the metal parts were worked to a needed shape by heating the workpieces to high temperatures and pressing them.

Forging processes include manual forging, machine forging, and stamping.

Manual and machine forging. In the first case, the heated metal is shaped manually by using the shock load of the tool (hammer or sledgehammer). The second type implies using special equipment with hydraulic presses or hammers (weighing up to 5 thousand kg) or forging machines.

Due to the complexity of the process, manual and machine forging types are only suitable for producing small forgings in small-batch manufacturing or individual production.

defects_in_ingots_and_forgings.jpgStamping is used in mass and serial production. In this case, the heated metal blanks are formed into the desired shape with a stamping press, allowing to obtain many identical forgings. Punch is used instead of a hammer to push into a workpiece.

Stamping has many advantages over hand forging because there is no need for workers with specific skills, and high productivity is guaranteed. In addition, the properties of resulting forgings include the highest uniformity possible while maintaining the minimum levels of roughness.

Defects in ingots and forgings

The violation of technical requirements, poor quality of primary ingots, equipment failure, incorrect cooling conditions – all these factors may affect the quality of resulting forgings. The defects of forgings may include transverse and longitudinal cracks, folds, flaws, non-metallic inclusions, and forging bursts.

Very important!  It is crucial to control the quality of forgings and identify defects in the primary pieces. This allows avoiding significant process losses and ensures the high quality of finished products.

Crack types. Assessment

Cracks can be both superficial and internal. Internal cracks are considered irreparable, while the surface crack can either be corrected with a number of finishing operations. The other way is to use the immediately used for further production of parts. In this case, it is necessary to evaluate the depth and length of the crack.

Several methods are suitable for this operation, including ultrasonic and eddy current testing. The two methods mentioned are widespread, but both have some shortcomings:

  • Ultrasonic testing requires a certified NDT inspector. The evaluation of the results usually takes much time;
  • Eddy current testing also requires certification. It is also associated with larger errors when applied to cracks deeper than 5 mm (0,19 inches).

crack_depth_meter-281m-mashproject_llc.jpgIf you need to obtain a quick result in millimeters that does not require decoding, we recommend using our Crack Depth Meter 281M.

 

Its main advantages include:

 

  • highly accurate results;
  • the memory of the device keeps scales for aluminum alloys, magnetic and austenitic steels;
  • sensors of different designs are available for cracks with a depth ranging from 0.5 to 100 mm (0,02 – 3,9 inches);
  • it is possible to perform measurements on curved surfaces thanks to the spring-loaded contact electrodes of the sensor.

 

Why we recommend the electrical potential Crack Depth Meter 281M

 

  1. Quick results do not require interpretation.
  2. The operator is not required to have a certification for ultrasonic or liquid penetrant testing.
  3. The costs of starting the usage of the device are low.
  4. Complete safety is guaranteed for users.

Attention! The crack meter was not designed to identify cracks but only to evaluate their depth. In case detecting defects is required, there are magnetic particle inspection, eddy current or liquid penetrant testing methods available.

Do not hesitate to check out our website for details about the price, technical characteristics, operation requirements, and delivery terms of our Crack Depth Meter 281M. If you are unsure whether the device is suitable for your tasks, write to us: mail@mashproject.ru.