Zidong Lin, Wei Ya, Vignesh Venkata Subramanian, Constantinos Goulas, Benedetto di Castri, Marcel J. M. Hermans & Belavendram Pathiraj

Wire Arc Additive Manufacturing of Stellite 6

Stellite 6 is a cobalt-based superalloy which has a good wear and corrosion resistance and retains these properties at high temperatures. Components are traditionally cladded with Stellite 6, using the Laser Metal Deposition (LMD) process, to achieve high surface performance and increase their service life. 

In this study, the WAAM technique (GMAW based – Panasonic robotic welding system) was employed to deposit Stellite 6 wire on S355 and AISI 420 steel plates. The advantages of the WAAM against LMD process include:

  • the higher deposition rate;
  • higher productivity;
  • higher material usage;
  • energy efficiency;
  • low hardware and wire feedstock cost.

On the other hand LMD process can achieve low dilution when depositing Stellite 6 [1]. 

In this study we showed that using the WAAM technique it is possible to deposit a Stellite 6 layer with a minimum dilution of 18.05% and 19.6%, respectively on S355 and AISI 420 substrate, preserving optimal material quality (Figure 1, and Figure 2). 

We have found Cr7C3 and Cr3C2 carbides, and Co4W2C intermetallic compounds in a Co-Cr-Fe solid solution (FCC) matrix in our investigation [2]. These phases can contribute to the final wear, corrosion and erosion properties of Stellite 6.

Stellite 6 can be found in hardfacing and corrosive application in a wide temperature range, valve components and impellers.

References

[1] Ya, W. (2015). Laser materials interactions during cladding: analysis of clad formation, thermal cycles, residual stress and defects.

[2] Lin, Z., Ya, W., Subramanian, V. V., Goulas, C., di Castri, B., Hermans, M. J. M., & Pathiraj, B. (2020). Deposition of Stellite 6 alloy on steel substrates using wire and arc additive manufacturing. The International Journal of Advanced Manufacturing Technology, 111(1-2), 411–426.

Figure 1. Stellite 6 microstructure after WAAM [2]

Figure 2. Deposited Stellite 6 layer on a) S355 and b) AISI 420 plate [2]

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