Nb–Cr complex carbide coatings on AISI D2 steel produced by the TRD process

  • Fabio Enrique Castillejo
  • Jhon Jairo Olaya
  • José Manuel Arroyo-Osorio
Technical Paper


Nb–Cr complex carbide coatings were produced onto AISI D2 steel by the thermo-reactive diffusion process to improve the surface hardness and corrosion resistance of this tool steel. The carbide coating treatment was performed using molten borax added with ferroniobium, ferrochrome and aluminum at temperatures of 1,223, 1,293 and 1,363 K during 2, 3, 4 and 5 h. The coating layers were characterized by optical and Scanning Electron Microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy and X-ray fluorescence spectrometry. The coating growth rates were evaluated, and a model of the layer thickness as a function of the treatment time and temperature was established. The hardness of the coating was measured by nanoindentation, and its resistance to corrosion was evaluated with electrochemical tests of potentiodynamic polarization. The produced carbide layers presented a homogeneous thickness as well as an improved hardness and corrosion resistance as compared to the uncoated steel.


Thermo-reactive diffusion coatings Nb–Cr complex carbides Corrosion Hardness 

List of symbols


Carbide layer thickness, cm


Diffusion coefficient, cm2/s


Processing time, s


Gas constant, J/(mol K)


Activation energy, kJ/mol


Absolute temperature, K



The present work was supported by COLCIENCIAS project No. 338 of 2011. We are also very grateful to the Universidad Nacional de Colombia and to CSM Instruments.


  1. 1.
    Arai T, Fujita H, Sugimoto Y, Ohta Y (1987) Diffusion carbide coatings formed in molten borax systems. J Mater Eng 9(2):183–189CrossRefGoogle Scholar
  2. 2.
    Arai T, Harper S (1991) Thermo-reactive Deposition/Diffusion Process. In: ASM handbook, Heat treatment, vol 4. ASM International, Materials Park, pp 448–533Google Scholar
  3. 3.
    Oliveira CKN, Benassi CL, Casteletti LC (2006) Evaluation of hard coatings obtained on AISI D2 steel by thermo-reactive deposition treatment. Surf Coat Technol 201(3–4):1880–1885CrossRefGoogle Scholar
  4. 4.
    Oliveira CKN, Muñoz-Riofano RM, Casteletti LC (2006) Micro-abrasive wear test of niobium carbide layers produced on AISI H13 and M2 steels. Surf Coat Technol 200(16–17):5140–5144CrossRefGoogle Scholar
  5. 5.
    Sen S, Sen U, Bindal C (2005) The growth kinetics of borides formed on boronized AISI 4140 steel. Vacuum 77(2):195–202CrossRefGoogle Scholar
  6. 6.
    Sen S (2005) A study on kinetics of CrxC-coated high-chromium steel by thermo-reactive diffusion technique. Vacuum 79(1–2):63–70CrossRefGoogle Scholar
  7. 7.
    Sen U (2004) Kinetics of niobium carbide coating produced on AISI 1040 steel by thermo-reactive deposition technique. Mater Chem Phys 86(1):189–194CrossRefGoogle Scholar
  8. 8.
    Sinha AK 1991, Boriding (Boronizing). In: ASM handbook, Heat treatment, vol 4. ASM International, Materials Park, pp 437–447Google Scholar
  9. 9.
    Su YL, Kao WH (1998) Optimum multilayer TiN-TiCN coatings for wear resistance and actual application. Wear 223(1–2):119–130CrossRefGoogle Scholar
  10. 10.
    Worrell WL, Chipman J (1964) The free energies of formation of the vanadium, niobium, and tantalum carbides. J Phys Chem 68:860–866CrossRefGoogle Scholar

Copyright information

© The Brazilian Society of Mechanical Sciences and Engineering 2014

Authors and Affiliations

  • Fabio Enrique Castillejo
    • 1
  • Jhon Jairo Olaya
    • 2
  • José Manuel Arroyo-Osorio
    • 2
  1. 1.Departamento de Ciencias BásicasUniversidad Santo TomásBogotá DCColombia
  2. 2.Departamento de Ingeniería MecánicaUniversidad Nacional de ColombiaBogotá DCColombia

Personalised recommendations