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Test: measuring the hardness between the rotor stages after the hardening


rotor_stages_after_the_hardening.jpgCustomer: a plant from Saint-Petersburg specialized in the production of equipment for hydraulic, nuclear, thermal, and gas turbine power plants.

Task description: for the first time the manufacturer faced the necessity to make Brinell hardness testing between the second and third stages of the rotor after the hardening. The distance between the stages is 81 mm. The customer's representative did not inform about the hardening depth.

To control the hardness of other equipment parts the manufacturer used the UCI Hardness tester TKM‑459CE since 2018. However, it is not possible to measure the given area of 145 mm with the standard sensor “A”.

Proposed solution: we offered to equip the device available at the plant with sensor "K" that has a smaller weight load of 10H, and which will:

  • provide a high-quality result, even if the hardening thickness is less than 100 mcm;
  • require less effort of the operator to press the sensor into the surface (important in case of an uncomfortable hand position);
  • suitable for work in confined spaces between rotor stages thanks to a short body of 76 mm.

Demonstration: the customer invited our experts to make a test measurement.

Before measuring a test block was used to check its performance with the new “K” probe. No extra calibration of the device was required.

The readings of the hardness tester obtained after the measurements of the needed rotor segment turned out to be within valid margins (190 – 240 HB on an unprepared surface). The representatives of the manufacturer were satisfied with the results.

Results: the customer decided to purchase the “K” probe with the weight load of 10H.

measuring_the_hardness_between_the_rotor_stages_2.jpg measuring_the_hardness_between_the_rotor_stages.jpg rotor_stages_after_the_hardening_2.jpg

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