
Posted by Jiri Sefcik on April 24, 2003 at 12:59:42:
Dear Sir,
I`d like to ask about plasma sprayed chromium carbide coatings.
How are the main principles how to get coatings with suitable properities. Especialy low porosity
and adequate hardness (about 850 HV0.3).
I have tried spray samples onto part (diameter 540mm) and I gave low hardness (450 HV0.3). I have
tried change the process parameters (primary/secondary gas flow, spraying distance) but the results
are not adequate. I think that it is due to decarburization of carbide component during spraying.
Process parameters:
-plasma gun: GTV 309MB
-plasma current: 500 AMPS
-prim.gas Ar flow: 52 slpm
-sec.gas H2 flow: 8.5 slpm
powder: Cr3C2+25NiCr 5-45micro m
carrier gas Ar flow: 4.2 slpm
part RPM: 35 rpm
trverse speed: 4mm/s
spraying distance: 80mm, 10mm, 120mm
Regards..............Jiri
jirisefcik@seznam.cz
Follow Ups:
Please go to the new Surface Engineering Forum as this old message board is a read only archive. Please copy and paste relevant information or link to this page if you wish to reactivate this thread on the new forum.