IGC and HIC test requirements

[Ahmed Abdullah]

IGC test is mainly required for austenitic stainless steels and nickel alloys to measure their susceptibility to this type of corrosion with respect to the standards ASTM A-262 and ASTM G28. Can someone explain to me if there are any conditions or limitations to apply this test. By that, I mean is IGC test required for all the austenitic stainless steels and nickel alloys in all cases (i.e sour service, high temperature service, etc.). Also, what are the conditions to apply HIC test?. Thanks in advance

 

[EdStainless]

the A262 test is not a corrosion resistance test. It is a test to detect sensitization (grain boundary carbide formation) in austenitic alloys. These alloys will still sensitize and suffer IGA in service, but they this is to show that they are not starting out that way.
Think of these as process verification tests.
When to use them? I would suggest every case expect where you are doing subsequent heat treatment.
HIC does not apply to austenitic alloys, this is an issue for steels.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[SJones]

IGC testing is usually applied by purchasers in the oil and gas industry as an element of manufacturing quality control. This can be seen in the requirements of NORSOK M-630, or IOGP S-563

https://www.iogp.org/bookstore/product/s563v02/,

for the alloys routinely deployed. A discussion of the testing rationale is given in NACE Corrosion 2007, Paper 07202. Similarly, HIC testing of carbon steel products is a quality control tool guided by ISO 15156-2 and NACE TM0284.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

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

 

[pradipgoswami]

Please read through ASTM A 262.The function of IGC testing, B,C,D,E are to detect the level of sensitization and loss of intergranular corrosion resistance. A262 Practice A is done as a quick screening test for 300 series steels, as explained previously. It's Oxalic Acid Etch Test for Classification of Etch Structures of Austenitic Stainless Steels.
HIC test has different intentions, mostly adopted for C.S. The referenced NACE standard is explained above. Additionally ISO 15156-3 explains the guidelines for Austenitic S.S and CRAs in sour service. Note passing of one test does not ensure that steel is good for the other test.


Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
ca.linkedin.com/pub/pradip-goswami/5/985/299