BLACK POWDER ON 440C AFTER PASSIVATION.
BLACK POWDER ON 440C AFTER PASSIVATION.
(OP)
HI, EVERYBODY,
I RUN INTO A PROBLEM HOPING SOMEONE CAN HELP ME DETERMINE WHAT MIGHT BE THE CAUSE OF THAT.
I JUST RECEIVED PARTS BACK FROM PASSIVATION WHICH HAVE LOOSE PITCH BLACK POWDER ALL OVER THE PARTS. THE POWDER CAN BE SMEARED OFF EASILY.
MATERIAL IS 440C, ROUGH MACHINED PRIOR TO HEAT TREATED TO Rc54~56, SEVERAL GRINDING OPERATIONS AFTER THAT. THEN GET MAGNETIC INSPECTED AND PASSIVATED.
THANK YOU ALL IN ADVANCE.
I RUN INTO A PROBLEM HOPING SOMEONE CAN HELP ME DETERMINE WHAT MIGHT BE THE CAUSE OF THAT.
I JUST RECEIVED PARTS BACK FROM PASSIVATION WHICH HAVE LOOSE PITCH BLACK POWDER ALL OVER THE PARTS. THE POWDER CAN BE SMEARED OFF EASILY.
MATERIAL IS 440C, ROUGH MACHINED PRIOR TO HEAT TREATED TO Rc54~56, SEVERAL GRINDING OPERATIONS AFTER THAT. THEN GET MAGNETIC INSPECTED AND PASSIVATED.
THANK YOU ALL IN ADVANCE.
RE: BLACK POWDER ON 440C AFTER PASSIVATION.
Or, it could be a result of a more agressive passivation resulting in a iron oxide smutt.
= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.
http://www.trent-tube.com/contact/Tech_Assist.cfm
RE: BLACK POWDER ON 440C AFTER PASSIVATION.
Is your processor using too strong an acid treatment, such as one appropriate for 304?
Michael McGuire
http://stainlesssteelforengineers.blogspot.com/
RE: BLACK POWDER ON 440C AFTER PASSIVATION.
THANK BOTH OF YOU FOR YOUR TIMELY FEEDBACK. DUE TO SEVERE DIMENSIONAL DAMAGE, .001 LOSS PER SURFACE, WE HAVE TO SCRAP OUT ENTIRE LOT. PROCESSING VENDOR ADMITTED IS THEIR MISTAKE HOWEVER HASITATE TO DISCLOSE THE DETAILS. THANKS AGAIN.