HIC and SCC tests could they be done on stainless steel?

[shawn6]

In order to prevent H2S corrosion of flare tip material it has been decided to use stainless steel material. The owner insists on HIC an SCC testing of stainless steel, is this done at any mills?

 

[cloa]

HIC?
SCC is obviously stress corrosion cracking.

 

[Corgas]

HIC (Hydrogen induced Cracking) occurs in carbon steel when you have wet H2S, that is, H2S and H2O.

Hydrogen is produced due to the corrosion reaction and permeates into the steel. There's a lot of information out there describing this process.

Stainless steel will not be afected by wet H2S; therefore, there won't be any HIC.

Check API 571, NACE MR0175 and/or NACE MR0103.

 

[SJones]

Flare tips are usually stainless steel or nickel alloys anyway. If there is H2S around, then strong consideration should be given to using 310 stainless steel. HIC is not an issue in these materials and it seems the end user is very confused! ISO 15156-3 or NACE MR0103, dependent upon the type of plant, will give materials requirements that, if complied with, remove the need to perform SSC testing. The end user also needs to recall that SSC will only be an issue if liquid water is present at the exposed surface of the material. Ask him to think about the temperature of the flare tip and the boiling point of water!

Steve Jones
Materials & Corrosion Engineer

http://www.oilandgaspeople.com/cv/11499664

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