×
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

AISI 321 corrosion

AISI 321 corrosion

AISI 321 corrosion

(OP)
We have in one instance, tremendous corrosion with AISI 321 used in a gas burner shaft. The gas burner reheat flue gas.
Outlet (shaft outside) is around 250-300°C
Inside (high temperatures, resulting from flame)

The only factor is that when we have corrosion, the flue gas outside contains HCl (hydrogen chloride), about 1000mg/m3 and some SO2.
The flue gaz would contain about 10%O2, some 15% water, about 10% CO2 and some dust.

Question:  would HCl/SO2 explain the difference in behavior, because experience is quite satisfactory on similar units where no HCl and no SO2 is present.  NO is always present.

RE: AISI 321 corrosion

Answer: Yes.

RE: AISI 321 corrosion

(OP)
Thank you, TVP.   May I ask what a suitable material would be?

RE: AISI 321 corrosion

How mich corrosion are you seeing?  Do you need something a little better, or a lot?

= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.
http://www.trent-tube.com/contact/Tech_Assist.cfm

RE: AISI 321 corrosion

(OP)
We need probably something that is a lot better. The shaft lasted for one month, before they were completly corroded
I am not a specialist in corrosion.  From the photographs, entire sections of shaft was "eaten" (loss of material).
The velocity around the shaft is not that high (10-15 m/s) so I think that erosion is not significant.

RE: AISI 321 corrosion

ALLOY C276 or Hasteloy C22 are exceptionally corrossion resistant to both wet and dry HCL. You might wish to check out their corrossion resistance to Sulphuric Acid and SO2.
Note these are very hard materials and can be difficult to machine if you are not experienced with them. They are also several times the price of austenitic stainless steels, but often a high price for the right material can work out lower cost in the long run

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