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Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing 1989-2024
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Post plate baking of EN coatings on low carbon steel parts
Hi,
Material: 1215MS Hardness: 400-700Hv before plating.
Process: Electroless nickel plating (MP) 4-5 micron
Does this require any post baking? If yes, please advise temperature & time. And what is the time difference between EN process & baking process?
After process, plated parts are sent for heat treatment by customer @ 280 °C for 1 hour with nitrogen atmosphere 10 ltr/min. How to avoid possibilities of blister & peel off at stage of heat treatment?
Process engineer - Salem, Tamilnadu, India
June 21, 2023
A. Hi Rajkumar,
Some EN plated parts are not baked, So, if the purchase order, drawing, and specification do not require post baking, I would say it would not be required unless there is a hydrogen embrittlement issue. Unfortunately in your case though, I believe there is such as embrittlement issue because the steel is medium to hard.
When components are heated to 280 °C for hardening, it can be a tough adhesion test, but properly cleaned, activated, and plated components are supposed to be able to survive it.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
⇩ Related postings, oldest first ⇩
Q. We use several components in our assemblies that are made from 1018 and 1215 steels. These parts are not case hardened nor heat treated and are electroless nickel plated. We currently call for a 4 hour post plate bake to eliminate the possibility of hydrogen embrittlement. I have had recommendations that the post bake is and is not required on low carbon steels plated with electroless nickel. Is there a definite guideline on when the post plate bake is required?
Dennis LimestallManufacturer of engine controls - Chicago, Illinois, USA
2004
A. Hydrogen embrittlement relief is required when hardened parts (either by heat treating or by severe forming/straining) have been exposed to hydrogen, usually either from electroplating processes or from acid pickling baths. The hardness level above which relief is required is > 320 HV (32 HRC) in SAE USCAR 5, or greater than 1000 MPa according to ASTM B850-98. This topic has been discussed here previously, so perform a search for more information.
Toby PadfieldAutomotive module supplier - Michigan
A. You did not mention bake temperatures. One reason that conventional EN is baked is to harden it. Hardening means improved wear resistance in some but not all cases.
James Watts- Navarre, Florida
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