Official Answer
Answer
316 Stainless Steel is an austenitic alloy with high molybdenum content, providing superior resistance to pitting and SCC in chloride-rich marine environments. However, it cannot be heat treated to high hardness, resulting in lower thrust capacities. 17-7PH is a precipitation-hardening stainless steel with much higher tensile strength but is more susceptible to SCC if not properly over-aged. For critical marine applications where load is high, 17-7PH in the CH900 condition is often used but must be carefully monitored. For the absolute best SCC resistance without compromising too much strength, nitrogen-strengthened alloys like Nitronic 50 or specialized Inconel grades are preferred.
