×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Rust Proof and chemical resistant coating for steels

Rust Proof and chemical resistant coating for steels

Rust Proof and chemical resistant coating for steels

(OP)
I have a mechanical assembly that will be attached to the head of a numerous engine types as a research and development tool. Unlike most assemblies on an engine head, this assembly is totally sealed and will not be exposed (externally)to engine oil. As a result, the system will rust. I need a coating that can be applied that will not allow rust to form.
During development the system will potentially be exposed to the following:
-Humid sealevel ambient conditions (including salt in the atmosphere)
-Engine oil (during assembly and dis-assembly
-Deisel Fuel
-Gasoline
-Solvents such as methanol (used to clean the parts)
-Carburator Cleaner
The materials I need to coat are - 4140 with a carbonitride coating and Grade 12.9 4037.

Does anyone have a suggestion of a coating I can use? This coating can be a "line-of-sight" type coating or chemical dip type coating (or any other type really). Please keep in mind I would like to apply this coating after heat treat so the coating process should not include heat exposure above the tempering temperature of the materials (400-450°C)

Thanks,
Chris Turner
719-686-6061
Sturman Industries
cturner@sturmanindustries.com
or cturner77@comcast.net

RE: Rust Proof and chemical resistant coating for steels

What about chrome?  It'll look nice, as well.

TTFN

RE: Rust Proof and chemical resistant coating for steels

(OP)
I would look at chrome, however probably as a last resort.  There are numerous internal features (including match fits for hydraulic actuators that are ~0.004 - 0.006mm diametral and other bearing surfaces) that would need to be masked so that the chrome plating would not occur in these areas.  I have also been warned by some metallurgists that hydrogen imbrittlement may occur.  Thanks for the suggestion and I will keep it in mind.  Also, do you (or anyone) know of some techniques used to mask parts that are to be chromed.

Chris Turner

RE: Rust Proof and chemical resistant coating for steels

Hydrogen embrittlement is a definite concern with electroplated chromium.

How about electrocoating?  It will provide corrosino resistance in your conditions, but may be somewhat costly for a single piece.

Actually, a good epoxy-based paint ought to work also.   

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

RE: Rust Proof and chemical resistant coating for steels

(OP)
Can anyone comment on using a CrN coating on top of an electrolys Nickel coating.  I have heard that this may work well.

RE: Rust Proof and chemical resistant coating for steels

CrN over electroless Ni is complete overkill for your application.  Those coatings are for wear resistance, not for appearance maintenance.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

RE: Rust Proof and chemical resistant coating for steels

If you really want a good corrosion resistant coating, consider IVD aluminum.  It's used extensively by the military as a replacement for cadmium plating.  It was developed many years ago at McDonnell-Douglas in St. Louis (now Boeing).

Jim Treglio
Molecular Metallurgy, Inc.

RE: Rust Proof and chemical resistant coating for steels

I like electroless nickel for the 12.9 fastener. For the 4140 part, if it is to be carbonitrided, you could consider one of the black salt bath nitride coatings, such as QPQ. Unless of course the 4140 part is already made and carbonitrided, then I would just go with the electroless nickel for that as well.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

White Paper - Strategies to Secure Connected Cars with Firewalls
White-hat hackers have demonstrated gaining remote access to dashboard functions and transmissions of connected vehicles. That makes a firewall a vital component of a multilayered approach to vehicle security as well as overall vehicle safety and reliability. Learn strategies to secure with firewalls. Download Now
White Paper - Model Based Engineering for Wire Harness Manufacturing
As complexity rises, current harness manufacturing methods are struggling to keep pace due to manual data exchanges and the inability to capture tribal knowledge. A model-based wire harness manufacturing engineering flow automates data exchange and captures tribal knowledge through design rules to help harness manufacturers improve harness quality and boost efficiency. Download Now
White Paper - What is Generative Design and Why Do You Need It?
Engineers are being asked to produce more sophisticated designs under a perfect storm of complexity, cost, and change management pressures. Generative design empowers automotive design teams to navigate this storm by employing automation, data re-use and synchronization, and framing design in the context of a full vehicle platform. Download Now
eBook - Simulation-Driven Design with SOLIDWORKS
Simulation-driven design can reduce the time and cost of product development. In this engineering.com eBook, we’ll explore how SOLIDWORKS users can access simulation-driven design through the SOLIDWORKS Simulation suite of analysis tools. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close