Treb,
I'm a machinist not a metallurgist, but I would imagine when the sulfur content is high, and is unevenly distributed (stringers) it would lead to weak spots, especially after pressure cycles.
Sulfur makes for EZ machining. You may have heard of "sulfur base cutting oil".
I can promise you that if the example I saw was in barrel steel, no way no how would it have passed any kind of proof. They actually looked more like cracks.
I would think there is a metallurgist here who could give us a more technical description.
Last edited by ithaca1; 02/02/16 09:17 PM.
