Hardness of Inconel 625 after ground

[demionkrishan]

Team,

Can anyone tell the required hardness of below material after spray and ground?
NI-328-5 / 1265F equal to Inconel 625
NiCrMoNb
(Atomized)

After ground and honed, i used to measure the diameter of the cylinder
by using bore gauge, i got few scratch marks. i feel the coating hardness is less. i have got only 25-30 HRC.

please add your comments..

Regards,
DK

[demionkrishan]

Below Parameters i have used

Gun SG100 Praxair
Primary gas as Argon 50
Secondary gas as Helium 110
Carrier Gas as argon 35
800A
38-39 V
Spray distance 3.75"
Spray rate 4lbs/hr

[Gordon]

Hi demionkrishan

You say 25-30 HRC, but what was the actual hardness test method and results?
What is the thickness of coating tested?

As a ball park figure 25-30 HRC equivalent is pretty much what to expect, though possibly a little harder depending on how it was sprayed.

[demionkrishan]

Hi demionkrishan

You say 25-30 HRC, but what was the actual hardness test method and results?
What is the thickness of coating tested?

As a ball park figure 25-30 HRC equivalent is pretty much what to expect, though possibly a little harder depending on how it was sprayed.

Hi Gordon,
Coating Thickness range is between 200-250 microns. I have used portable hardness tester, Rockwell C scale. it is cylindrical part so i can't get accurate reading. while i insert the piston, i found some scratch mark. so i feel my coating is smooth. May i know the Actual hardness of Inconel 625 after ground?