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Is killed carbon steel HIC resistant 3

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Mechh007

Mechanical
Jun 21, 2012
41
Hi folks,
Please help on the following question.
is killed carbon steel HIC resistant? and I heard SA106 Gr.B pipes are suitable for wet H2S service lines, why don't we use SA53 Gr.B Pipes?

 
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I bought a lot of wet H2S service vessels, basicaly knowing that killed CS is not automatically HIC resisttant. In wet H2S service, depening on the concentration, there are two type of HIC materials: HIC resistant (used in simple H2S service) and HIC tested (used in severe H2S service). In severe service, we normalize every material, including SA-105 and SA-106B. I am just a vessel engineer, following the spec made by material engineer. I recommend you to post similar thread in "Boiler and Pressure Vessel Engineering" if you don't get any response in 2-3 days, there MVP metengr and other people knowing the service will give you better inside.
 
Lots of things go into HIC resistance:

Deoxidation
Vacuum degassing
Fine grain practice so that ASTM grain size = "x" or smaller
Trace chemistry
Alloying elements
Method of manufacture
etc.

But the "acid test" (pardon the expression) is whether or not unacceptable cracks develop in prepared specimens after continuous exposure to one of two standard acid solutions (see NACE Tm 0284). I believe that most producers and metallurgists have their own variations regarding what defines acceptable versus rejectable, but one common generally accepted measure is based on criteria published by Prudential Steel. Namely, PS-10 and PS-50 levels of HIC - resistance.

Beware of the term "HIC Resistant". All it really means is that the steel's manufacture has been controlled in such a way as to be consistent with that for other steels that have subsequently demonstrated acceptable levels of crack development after a HIC test. It does not mean that the steel would actually be guaranteed to pass a test if you were to impose it.
 
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