Oxide stringers in Metco 58NS coating

[thezombiesprayer]

Hi all

I have some problems with occasional clusters of oxides and odd shaped unmelts in my Metco 58NS coating coupons after cut up.
Is this due to my parameter settings?

My powder batch has not changed for the last 3 months and we didnt have much problem with the microstructure of this coating coupons until this. We only have some round unmelts sometimes which is acceptable per requirement.

Appreciate your advice asap.

Thanks

thezombiesprayer

[loriolo]

Please look at the powder injector for powder accumulate on it, that can cause a deviation of the stream, or some time can release some dirthy on the spray stream.

[thezombiesprayer]

Please look at the powder injector for powder accumulate on it, that can cause a deviation of the stream, or some time can release some dirthy on the spray stream.

Thanks! I shall check out the injector when they spray the coating next time. I just checked out that the chiller of the machine was leaking a week or 2 ago. Not sure will this contribute largely to increase of oxides and elongated unmelts too.