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Why is chrome not plating properly on Nimonic 80A material?

adv.    

2005

We have a product with the material of Nimonic 80A to be chrome-plated. But we find poor adhesion, peeling off and partial deposition on that material. We are trying for this material at first. But our bath is proper working for other ferrous materials. Please, give me some solutions.

Chemistry of Nimonic 80A: (This is for your reference)

C 0.1 max
Si 1.0 max
Mn 1.0 max
Cr 18-21
Ni Balance
P 0.045 max
S 0.015 max
Ti 1.8-2.7
Al 1.0-1.8
Fe 3.0 max

Thanks in advance

V. Ranga Bhuvana Balaji
Process Shop - India

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First of two simultaneous responses --

Try to read your own letter again, and you will find that you already gave the reason yourself. This is not a ferrous material, its more than 70 % nickel and only 3 % iron. You will need to activate nickel.

Bo König
Food industry - Odense, Denmark
2005

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Second of two simultaneous responses --

You need a strike of Woods after proper cleaning to activate the surface. Then proceed w/no delay to subsequent baths.

Guillermo Marrufo
Monterrey, NL, Mexico
2005

Thank you for your kind reply. And can you suggest and procedure or change in bath parameters? And can you tell me the procedure to activate nickel?

V. Ranga Bhuvana Balaji
Process Shop - India
2005

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Mr Balaji,
After pretreatment go for chrome without reverse etch. hope this will solve your problem .

regards

Qutub Saify
- Ajman, UAE
2005

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First clean very very good with hot water and keep this hot 55 deg.

Second put the nimonic in to the bath with current (2-2,5 V), we call this "live entry".

Leave with current about 7-9 A/dm2 for 180 sec. You will see H2 production on Nimonic.

Increase the voltage by 1 V per min.

Arrive to 50 A/dm2

NEVER NEVER reverse etch.

Papapanos Giorgos
- Athens, Greece
June 23, 2010

adv.