Thread 16/22

Cadmium stripping on high strength steels

What is a good non-cyanide method for stripping yellow chromated cadmium from high strength steels (>43 HRc)? Sodium hydroxide bleaching and ammonium nitrate stripping leaves behind a white residue.

Mandar Sunthankar
- Fort Collins, Colorado
1998
publicly reply to Mandar Sunthankar

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After using ammonium nitrate, remove the residue in 10 % hydrochloric acid ( inhibited with glycerine ) , then clean anodic in alkeline cleaner . Heat treat for 2 -3 hours at 190 c , to remove embrittlement . Bleaching is not required dip parts in the cleaner first .

Problem solved .

Dave Brackenridge
aerospace plating - Germiston, South Africa
1998
publicly reply to Dave Brackenridge

Dave, what if I do the HCl clean first to dissolve chromate layer, then strip in nitrate? I am not willing to touch HCl to the kind of parts I receive. Also, how much glycerine do I have to add to inhibit HCl?

Mandar Sunthankar
- Fort Collins, Colorado
1998
publicly reply to Mandar Sunthankar

I need to know what causes propeller blade burn when using hot solution while anodizing for cadmium plating.

Ed Davidson
- SCS - Birmingham, Alabama
1998
publicly reply to Ed Davidson

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