SCC (CFC) with HCL or HF?

[jackboot]

Question:

Would concentrations of 15% HCL and/or 12:3% HCL:HF likely cause SCC or CFC?

Given: 4300 series alloy steel 330 BHN (130 YS), ambient temperatures, cyclic loading with high stresses (localize areas).

My initial guess is - yes.

jackboot

 

[mcguire]

Absolutely. It may be masked by the aggressive attack these media would have on this material, but this strength level is above the roughly 95,000 YS needed for susceptibilty, so all you need to do is exceed a modest threshold stress level.

 

[jackboot]

Thank you Mcguire

Where do you find the 95,000 YS as being the limit for susceptibility?

And what stress level would the threshold?

I have been reading everything I can get my hands on but I can't find the limits on these two triggers?

jackboot

 

[unclesyd]

mcguire should have put a little more emphasis on
ABSOLUTLY[/color red]
If your fasteners are anywhere near the solutions especially the HCl you should consider them broken with a little time. I might argue with mcguire about the threshold stress level(a good value to work with) but not the end results in your case or any case around the acids by direct contact as in cleaning or in proximity of the vapors.
We been having a discussion in another thread concerning Hydrogen Embrittlement caused by corrosion, you have a prima facie case.
One thing to remember is that materials don't have contact the acids as the vapor under the right conditions will concentrate to much higher levels. Condensation droplets above a 1% HCl solution will concentrate to 27% acid. HF is not as bad but concentrate.