It has been important for the oil industry to establish reliable test method(s) for qualification and safe utilization of subsea pipelines and components made from stainless steels. This paper describes a method that has been developed through a JIP executed with support from leading oil companies and meterial suppliers.p
Experience has shown that stainless steels can suffer from Hydrogen Induced Stress Cracking (HISC) under cathodic protection in seawater. This paper presents results from a test program examining the HISC susceptibility of 25% Cr super duplex stainless steel (UNS S32750) at temperatures up to 1500C.
In the oil and gas industry, the major standard for material selection today is ANSI1/NACE2 MR0175/ISO 15156 Parts 1-3.  While this standard deals extensively with environment cracking and its prevention for materials under exposure to production environments containing H2S, CO2, chlorides, and sulfur, it does not include any guidance or material requirements for resistance to environmental cracking (such as hydrogen stress cracking – HSC, or otherwise) under variable subsea conditions that involve exposure to seawater with varying levels of cathodic protection (CP). ISO 21457  provides further guidance for materials selection and corrosion control for oil and gas production systems but does not provide adequate coverage of the issue of environmental cracking in subsea applications with CP.
Cast Iron with its ancient history, traced back to 6th century BCE1, has been used for centuries to anything from manhole covers & fire hydrants to bridges. However, the development of Spheroidal Graphite Cast Iron (SGCI) or Nodular Cast Iron, in the 1940’s, with resulting improvement in mechanical properties such as ductility and fracture toughness, paved the way for further growth in industrial usage of cast iron.2 The material has been adopted by several industries such as automotive-, nuclear-, and wind turbine industry. During the last decade, SCGI has gained increased attention as construction material for subsea equipment in offshore oil & gas production, mainly competing with welded and bolted steel assemblies.