Application Limits for Martensitic Stainless Steel Forged Bar-Stock Alloy UNS S41500 (F6NM)

摘要

A Sulphide Stress Cracking (SSC) test program has been undertaken on candidate forged bar stock martensitic stainless steel alloy UNS S41500 (F6NM) supplied by two different manufacturers. The program comprised of sustained load stress corrosion tests, generally in accordance with NACE TM0177-2005 Method A. The main exception was that a range of test conditions were used. This included test solutions with two different chloride contents and pH levels ranging from 4.0 to 5.5, plus hydrogen sulphide contents in the conditioning gas ranging from 0.5 to 100kPa. The results of this test program are presented as Sulfide Stress Cracking domain diagrams for both manufacturers alloy.