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Phosphate Insulation Problem

Greetings, My name is Luis Ramirez and I'm having a problem with a phosphate insulation process. The part we process is made out of steel of .035" thk X .72"L X .30W. This part is fabricated, later hardened, cleaned and finally the phosphate process. The intention of this phosphate is to insulate this steel part since it may create a secondary current path or weld to another steel component. The phosphate process has been very painful since about 10 to 20% of the parts do not get much of this insulation. We have tried everything in our reach but it seems that the problem comes and goes without any logical explanation. I need to know if there is an alternative process that any of the experts in this forum could help us find.

Best Regards

Luis Ramirez
- Vega Baja, PR
2000

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2000

A phosphating problem that comes and goes, and results in reject rates of 10 to 20% may indicate, without any more information than this:
1. Check the cleaning cycle because, especially after heat treatment, you may have an oxide coating or even a baked-on organic coating which is not coming off during cleaning.
2. If a barrel process, you may have nesting or sticking between parts.
3. Check the alloy for suitability for phosphating.
Regards, Tom

  
Tom Pullizzi
Falls Township, Pennsylvania