The hardness values of weldments of supermartensitic stainless steels exceed limits for “sour service” and testing has to be done. Most testing has been done by procedure defined in EFC Publication No 172. Some observations during testing have led to a discussion on the relevance of the test methods and procedures.
Low Cr (3 to 5%) bearing steels have been developed and used in CO2 environment as materials to meet "Fitness for Purpose". However, the SSC and SCC resistance of low Cr bearing steel have not been clarified. This paper presents the effect of carbon content, microstructure, and tempering temperature on the SSC and SCC resistance as well as CO2 corrosion resistance of low Cr steel (3%Cr steel).
Alternatives to cadmium plating on fasteners have been evaluated for a number of years. Torque-tension and corrosion resistance characteristics have been the major concerns. Zinc plating has been a popular substitute, but torque-tension at proper preloads on Grade 8 fasteners requires more torque. Torque-tension tests were ALSO evaluated on Grade 5 fasteners - same coatings.
Structural, ballistic, and mobility requirements have led to the selection of aluminum alloy 2519 as the primary structural material for the Advanced Amphibious Assault Vehicle (AAAV). Two-year seawater alternate immersion exposures of welded AI 2519 panels with and without protective coatings were conducted to simulate the expected AAAV service environment.
A new wrought alloy has been developed for use as furnace tubes in ethylene pyrolysis plants. This alloy has an excellent carburization resistance due to uniform formation of protective Al2O3 oxide scale on the metal surface. Laboratory corrosion tests have been carried out to evaluate carburization resistance of the developed alloy.
In context of acceptability of 17-4 PH in sour service, an literature survey of complex metallurgy of this grade was done following a mechanical rupture in service. In addition, three 17-4 PH materials were studied in terms of microstructure, mechanical properties and susceptibility to sulfide stress cracking.
Nickel-base alloys 718, 725, and 925 are commonly used in oil and natural gas production. Being heavily alloyed multi-component systems; these materials require special consideration for processing and heat treatments. This paper shows the effect of intergranular precipitates on mechanical properties and slow strain rate (SSR) test results in sour oil patch environments.