Sites: GlobalSpec.com | GlobalSpec Electronics | CR4 | Electronics360
Login | Register
The Engineer's Place for News and Discussion®

Previous in Forum: water monitoring   Next in Forum: Chemical composition of steel
Close

Comments Format:






Close

Subscribe to Discussion:

CR4 allows you to "subscribe" to a discussion
so that you can be notified of new comments to
the discussion via email.

Close

Rating Vote:







2 comments
Associate

Join Date: Jan 2007
Posts: 34

corrosion resistance of SS 410

11/27/2008 12:15 AM

We purchased Twin screw extruder. We had given specifications for contact parts (i.e. barrel and screw elements) to be made of SS 410. Manufacturer supplied the machine stating that contact parts to be of SS 410. We are processing wet maize starch in the extruder. Normal iron content of maize starch is 10 ppm, whereas after we processing wet starch in extruder we are getting iron content 100 ppm. There was very high contamination of iron in the material. After opening extruder we foung there rust on all screw elements but no rust on barrel portion (stationery part).

I want to know:

1. Does SS 410 has adquate corrosion against neutral water at 120 degrees centigrade

2. If it does have the corrosion resistance, why are we getting rust. Could it be that manufacturer has supplied us wrong material of construction.

3. How to veryfy if the material of construction is SS 410

4. If SS410 is unsuitable what could be alternative MOC for extruder having good hardness equivalent to SS410.

Register to Reply
Pathfinder Tags: Corrosion material of construction resistance ss 410
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Power-User

Join Date: May 2007
Posts: 273
Good Answers: 5
#1

Re: corrosion resistance of SS 410

11/27/2008 2:56 AM

SS 410 is a martensitic staniless steel. Stainless Steel are resistant in neutral water even at 120°C. Are you sure that the pH is neutral? if the rust is on the screw could it be a problem of erosion-corrosion, there are solid particles in the fluid?

S

corrosion prevention & protection

Register to Reply
Guru
United States - Member - USA! Hobbies - Musician - Sound Man Engineering Fields - Mechanical Engineering - More than a Hobby Technical Fields - Technical Writing - New Member

Join Date: Oct 2008
Location: City of Roses.
Posts: 2079
Good Answers: 99
#2

Re: corrosion resistance of SS 410

11/27/2008 2:56 AM

SS 410 must be hardened for maximum heat and corrosion resistance. Performance is best with a smooth surface finish. It's Less corrosion resistant than the austenitic grades of SS.

2. Possibly the "screw elements" were not properly heat treated, hardened, and polished?

2. Could the material/s your running thorough the extruder be putting tiny scratches on the surface of the "screw elements" causing them to corrode?

1. SS410 resists dry atmosphere, fresh water, mild alkalies and acids, food, steam and hot gases, Good resistance to scaling up to approximately 650°C, but generally not recommended for use in temperatures between 400 and 580°C. So i would assume it should be ok.

3. hydrochloric Rapid reaction - produces dark green solution

3. spark test produces Long white with few forks

4. 420, or 440C maybe?

http://www.engineeringtoolbox.com/identification-stainless-steel-d_383.html

__________________
Don't believe everything you read on the Internet!
Register to Reply
Register to Reply 2 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Previous in Forum: water monitoring   Next in Forum: Chemical composition of steel
You might be interested in: Rust Preventives and Corrosion Inhibitors, Conical and Telescopic Screw Covers, Corrosion Probes, Coupons and Holders