Pickling and Passivating of Welded Carbon Steel Pipes
Hi everyone,
I am a student from the Metals and Materials dept at UBC, Vancouver, Canada. I'm looking for information on the pickling and passivating of welded carbon steel pipes. I've been searching for this info in the libraries and on the net and the only thing that I'm able to find is on stainless steel. Would anyone have any suggestion on this issue or where I can look up this info (I've checked the ASTM standard and the standard is also on stainless steel).
Thank you very much for the help :)
Winky LaiUniversity of British Columbia
----
I've never heard of passivating carbon steel, Winky. It seems like there would be a lot less call for zinc plating, galvanizing, phosphatizing, painting and powder coating if such a thing could be done; I don't think it can. You might look up Corten® steel though, or see if
ASTM A569 [link is to "Download ASTM Standards" from ANSI.org]
gives any specifics on the pickling.
|
 Ted Mooney, P.E. RET finishing.com Brick, New Jersey |
---
"CORTEN" is a trade name for this alloy of steel. US Steel owns this name. This is known as a HSLA steel. Which means hi strength low alloy. It has only .09% carbon (low alloy).
Tensile is 70,000 psi. Mild steel is only 60,000 psi. Contact US Steel for full details. ASTM A242 is another designation too. Good luck.
Stephen D. Yahn+
Have experience of using CORTEN steel for ship funnel main engine exhaust pipe? Does it really prevent rust? How will it look (external) after say 2 months of operations? Exhaust temperature expected approximately 500 deg C. External factors - Tropical climate.
Chan YK- Singapore
+
I have some experience for carbon steel passivation using sodium nitrate solution. This will create a thin film of oxide which can prevent the carbon steel form corrosion. However I am not sure how long/effective this technique is...
Hisham- Kuala Lumpur, Malaysia
++++
Pickling and passivation of carbon steel is relatively uncommon when compared to stainless steel, however I have been involved with large scale pickling and passivation of carbon steel piping for installation at a plant in Mozambique. The pickling and passivation was carried out in Durban (South Africa) and I was in charge of the entire project. The finished product was then shipped up to Maputo by road
Regards,
Mike O'Mahoney- Bracknell, Berkshire, UK
November 28, 2008
Hi, Mike. We understand what pickling is (the removal of scale), why it is done, and how it is done. But I am not understanding what you mean by passivation of mild steel, i.e., what it is, why it is done, or how it is done. What property is claimed for passivated mild steel? Thanks.
Regards,
|
Ted Mooney, P.E. RET finishing.com Brick, New Jersey |
October 20, 2009
i want pickling and passivation details & definition.Is it possible to do C.S. MATERIALS?
B.Sudharsanan- CHENNAI, India
October 21, 2009
Hi, B. A problem here is that passivation doesn't have an exact meaning. The most common meaning applies to stainless steel, where nitric acid or alternatives serve to chromium enrich the surface and form a chrome oxide skin. So, when people talk about passivation of carbon steel, what exactly do they mean -- certainly not chromium enrichment.
Some people call chromate conversion coating of zinc plating 'passivation', and others call phosphatizing of steel 'passivation'. Phosphatizing or a similar treatment does offers some degree of rust prevention.
Can you provide context? Texts such as the Electroplating Engineering Handbook provide fairly detailed information about pickling and passivation. Good luck.
Regards,
|
|
Ted Mooney, P.E. RET finishing.com Brick, New Jersey |
