Fusing of cast iron

[Arturas]

Hello,
I have such problem: I need to regenerate and to increase wear resistant of parts (Working conditions: transporting of steel sticks (temperature 900C))whish are made from grey cast iron. I tried to did it by using fusing of self fluxing coatings, but there appears cracks of coating and distortion of part.
I find material "Metco 439NS"As-sprayed coatings are partially fused and require no further fusing, which makes them ideal for use with substrates that can not tolerate the fusing temperatures required by the self-fluxing alloys). Maybe it is solution????? And how to understand partially fused? (What temperature, properties of coating , adhesion resistant to impacts and so on????
Thanks
Regards, Arturas

[Gordon]

Hi Arturas

Terms like "self-fusing" and "self-bonding" can be misleading. My interpretation of these terms:

"self-bonding" - a coating that is capable of bonding to a clean polished or ground steel substrate. usually requiring no bond coat or can be used as bond coats.

"self-fusing" - basically a coating containing self-fluxing alloys and sometimes aluminium as well. These coatings can show good strength and properties, but still retain typical properties of thermal spray coatings and should not be classed as a direct alternative to fused coatings which have very different properties.

Metco 439 is designed for plasma spraying and is a possible candidate for this application. Possibly better, HVOF coatings of WC/CoCr, chromium carbide/NiCr, stellite 6 and similar have had varying degrees of success with this type of application.