The influence of heat treatment on properties of steel for cementation

  • 1 Faculty of Mechanical Engineering, University of Osijek, Slavonski Brod, Croatia
  • 2 SaTCIP Publisher LTD., Serbia
  • 3 Agricultural High School Matija Antun Reljković, Slavonski Brod, Croatia


During the injection molding procedure of plastics, the gear pumps in their work are exposed to the effect of elevated pressure and temperature. On one of these pump there has been frequent downtime due to breakage of the driven gear. Gears which were installed as standard spare parts had stood out in operation for three months. On a sample of a broken gear were perfomed laboratory examinations (metallographic examinations, hardness control on cross-section and surface of the fracture was examined). Conclusion was that it was high quench hardening of a steel of which a part is made, the most likely cause of the fracture of a standard gear. In order to extend the useful life, two test gear are made from steel for cementation 20MnCr5. By applying the appropriate parameters of thermal chemical treatment useful life of the gear is significantly extended, after which the test gears have worked for nine months from the moment of installation.



  1. Khan, R. M.; Acharya, G.: Plastic Injection Molding Process and Its Aspects for Quality: A Review, European Journal of Advances in Engineering and Technology (2016) 3-4, 66-70.
  2. Brnic, J.; Brcic, M.: Comparison of Mechanical Properties and Resistance to Creep of 20MnCr5 Steel and X10CrAlSi25 Steel, Procedia Engineering 100 (2015), 84-89.
  3. Belahssen, O.; Benramache, S.: Improving Tribological Properties of 20MnCr5 Steel by Plasma Nitriding, Journal of Chemistry and Materials Research 4 (2015) 2, 45-48.
  4. Brnic, J.; Turkalj, G.; Lanc, D.; Canadija, M.; Brcic, M.; Vukelic, G.: Comparison of material properties: Steel 20MnCr5 and similar steels, Journal of Constructional Steel Research 95 (2014), 81-89.
  5. Grilec, K.; Jakovljević, S.; Marić, G.: Tribologija u strojarstvu, Fakultet strojarstva i brodogradnje, Zagreb, 2015.
  6. Krumes, D.: Toplinska obrada, Strojarski fakultet u Slavonskom Brodu, Slavonski Brod, 2000.
  7. Marković, R.; Milinović, A.: Microstructure and properties of duplex (C + N) layers, Technical Gazette 16 (2009) 1, 25- 29.
  8. DIN 50190: 1979. Case Hardness Depth (CHD) Measurement.

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