The PREN calculation gives engineers a single number for comparing the chloride pitting resistance of stainless and duplex alloys without juggling 3 separate element ranges. This post covers the formula, 5 worked examples with the full arithmetic shown, what the
Super duplex S32750 or hyper duplex S32707? Compare PREN, pitting resistance, and yield side by side, and learn exactly when the stronger corrosion performance of S32707 is worth the premium, and when S32750 is still the right call.
Seawater at roughly 19,000 ppm chloride damages standard stainless steels, and material selection mistakes show up as pitting failures within months of commissioning. This guide compares four candidate alloys for seawater piping: UNS S31603 (316L), UNS S31254 (6Mo super-austenitic), UNS
Use PREN to shortlist candidate grades, then specify CPT testing on the actual production heat to qualify it.
Duplex and super duplex stainless steels share the same dual-phase microstructure. Both contain roughly 50% austenite and 50% ferrite. But super duplex pushes the alloy content higher, giving it a PREN above 40 and a yield strength above 550 MPa.
Both 304 and 316 are austenitic stainless steels that resist corrosion, handle high temperatures, and weld easily. One critical element that separates them is molybdenum. This element improves corrosion resistance and affects both performance and cost. This comparison covers chemical
Incoloy 825 and Inconel 625 are both nickel-based alloys built for extreme corrosion resistance. But they differ in nickel content, molybdenum levels, temperature capability, and cost. An incorrect alloy selection can result in unnecessary cost or premature equipment failure. This
Wall thickness determines how much pressure a pipe can handle, how much it weighs, and how much it costs. Selecting a wall that is too thin risks burst failure. Pick a wall that is too thick, and you waste money
Ordering stainless steel pipe without understanding NPS, schedule, and OD leads to wrong sizes, wasted material, and project delays. These 3 dimensions define every pipe you buy, but they confuse even experienced engineers. This guide explains how NPS, schedule, and