×
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

Jobs

Zinc plate for Bolts and nuts exposed

Zinc plate for Bolts and nuts exposed

Zinc plate for Bolts and nuts exposed

(OP)
Hello, everybody.
There is inside Nace MR0175/ISO15156(2):2009; A2.1.5 a mention about the metalic coatings. That is a not acceptable for preventing SSC. For standard we offer the bolts and nuts to attend NAce with Zinc plated. The material is correct with Nace (B7M-2HM). Our intention is not preventing SSC. Could we provide plated or nude bolts and nuts ?

RE: Zinc plate for Bolts and nuts exposed

I believe that you need a rusting prevention and I don't know the place of your construction or use. Anyway, only zinc plated is not satisfactory for marine enviroment. I prefer Zn-Ni for this case. In case of bolts and nuts the only problem is not corrosion resistance but abrasion resistance for the threads when you are bolting. Think about the disassembly of bolts and the plate status. There is a lot of methods that make me prefer Zn-Ni. See ASTM-B-850 that talks about the post heat treatment to avoid hydrogen embrittlement. If you provide no plated bolts and nuts but shot blasted and painted after the conclusion of the job you will have corrosion protection on the seen area but no protection on the others parts, so maybe it will be not a good solution and it depends of your enviroment.

RE: Zinc plate for Bolts and nuts exposed

If it is under NACE Requirement, then I guess it is a highly corrosive environment.
If it is not, why you are referring NACE MR0175. (Off-shore).

It is not recommended for Nude Bolts and Nuts. It should be coated/plated by Zinc-Ni plated or according to
your specs.

RE: Zinc plate for Bolts and nuts exposed

(OP)
Thanks a lot, friends. I will thinking a little more.

RE: Zinc plate for Bolts and nuts exposed

The meaning of the ISO 15156-2 statement is that it is not acceptable to use a coating as a means of rendering an unqualified substrate acceptable for H2S service. Since the B7-2HM would be considered as qualified for H2S service, the application of a coating is not restricted.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

All answers are personal opinions only and are in no way connected with any employer.

RE: Zinc plate for Bolts and nuts exposed

Vendor should do a post-bake operation for zinc plated fasteners to prevent hydrogen embrittlement.

Have a look at BS 7371 and Shell ES/313 to have a better idea.

RE: Zinc plate for Bolts and nuts exposed

(OP)
Hello, guys.
Their informations are all that I need to decide to do. Thanks a lot.

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!


Resources