Identify suitable range of technical parameters for the best porosity of Cr3C2 – NiCr coating on C45 steel by high velocity oxygen-fuel spraying method (HVOF)

Nowadays, spray coating technology has been developed and widely applied in developed countries. One of the spraying methods which are most commonly used in industry is HVOF. Basically, coating layers created by HVOF are very complicated, its characteristics and microstructure strongly depend on spraying technical parameters. This paper presents experiment result of spraying Cr3C2-NiCr on 40Cr by HVOF. On the other hand, the effect of some spraying technical parameters to the porosity of coating layer is also analyzed. From experimental results, a suitable range of spraying technical parameters has been identified that could be applied to recovery shaft type wearing parts.