Enhanced wear resistance of Stellite 12 by Mo addition and LSM^*

* This paper was part of The 31st Edition of the International Conference on Surface Modification Technologies (SMT 31) held at University of Mons, Belgium, on 05 06 and 07 July 2017.

ABSTRACT

Aiming at additional improvements in the properties of Stellite 12 PTA hardfacing alloy deposited on 4140 steel substrate, the authors have adopted a dual approach. During PTA deposition Stellite 12 hardfacing powder was alloyed with 10 wt-% Mo, followed by laser surface melting (LSM). Addition of 10 wt-% Mo, led to an increase in the volume fraction of Co and W-rich complex carbides. Later on LSM executed on the PTA led to the development of unique microstructure near the surface, characterised by the segregation of hard Cr-rich carbides. The resultant layers were subjected to mechanical characterisation, at room temperature, e.g. hardness and wear resistance. It was concluded that combining both approaches i.e. addition of Mo during the hardfacing process followed by LSM of deposited layer gave additional improvements in mechanical properties owing to evolution of a unique carbide structure.

KEYWORDS:

• Hardfacing
• Stellite
• molybdenum
• laser surface melting
• wear
• carbides

Acknowledgements

Assistance in SEM studies, by Mr Ahmet Nazim of Gebze Technical University, Turkey, deserves special thanks. Authors are also grateful to Senmak Co., Turkey, for the provision of PTA facility.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

* This paper was part of The 31st Edition of the International Conference on Surface Modification Technologies (SMT 31) held at University of Mons, Belgium, on 05 06 and 07 July 2017.

Additional information

Funding

Authors are also grateful to the Higher Education Commission of Pakistan for PhD study grant for Shaikh Asad Ali Dilawary at Istanbul Technical University, Turkey.