flame spray hardness too low

[joanwang]

Hi,Gordon
Another question is the flame spray sample of Metco314NS hardness too low,with the same parameter we spray before,now the HR hardness only 20-30,but at before it's 55 around.we changed powder feed rate,Oxygen&Acetylene flow,one item one time.it doesn't work.which parameter do you suggest to adjust foremost?
And any other function of the gun cooling air excpet for cooling the gun?
Thank you!
Joanwang

[pabloarriola]

Hi,Gordon
Another question is the flame spray sample of Metco314NS hardness too low,with the same parameter we spray before,now the HR hardness only 20-30,but at before it's 55 around.we changed powder feed rate,Oxygen&Acetylene flow,one item one time.it doesn't work.which parameter do you suggest to adjust foremost?
And any other function of the gun cooling air excpet for cooling the gun?
Thank you!
Joanwang

Hi,

Maybe you have a problem with your equipment? If you receive no alarm, probably the problem is located between the jambox/control box and the gun. I am not familiar with HVOF, but I have experience with plasma guns. Check for any gas leakage on the hoses. And check the gun, be sure that there is no crack that allow the cooling water to pass to the combustion area.

Good luck!

Pablo

[Gordon]

Hi Joanwang

to the Surface Engineering Forum.

Hi,Gordon
Another question is the flame spray sample of Metco314NS hardness too low,with the same parameter we spray before,now the HR hardness only 20-30,but at before it's 55 around.we changed powder feed rate,Oxygen&Acetylene flow,one item one time.it doesn't work.which parameter do you suggest to adjust foremost?
And any other function of the gun cooling air excpet for cooling the gun?
Thank you!
Joanwang

With Metco 314NS, strictly follow the recommended parameters, adjusting only the acetylene flow; reducing flow to lower hardness, increasing flow to increase hardness. If you can not achieve the 50 +/-5 HR15Y then suspect equipment/process problem or problem with powder batch. 20-30 does sound very low. Try increasing Acetylene flow, if this does not increase hardness to correct level, then there is little point in messing with other parameters. The problem will be with the equipment or powder.

And any other function of the gun cooling air excpet for cooling the gun?

6P 3 air cap can be place in two positions; one to give gun cooling only, the other to give pinch air, which pinches and cools spray stream as well as cooling gun.

[Gordon]

Hi Pablo

to the Surface Engineering Forum.

Hi,Gordon
Another question is the flame spray sample of Metco314NS hardness too low,with the same parameter we spray before,now the HR hardness only 20-30,but at before it's 55 around.we changed powder feed rate,Oxygen&Acetylene flow,one item one time.it doesn't work.which parameter do you suggest to adjust foremost?
And any other function of the gun cooling air excpet for cooling the gun?
Thank you!
Joanwang

Hi,

Maybe you have a problem with your equipment? If you receive no alarm, probably the problem is located between the jambox/control box and the gun. I am not familiar with HVOF, but I have experience with plasma guns. Check for any gas leakage on the hoses. And check the gun, be sure that there is no crack that allow the cooling water to pass to the combustion area.

Good luck!

Pablo

Thanks for your input.