ITA lauds successful completion of Grade 12 update

The International Titanium Association’s Industrial Applications Committee has confirmed that the project to update Titanium Grade 12 requirements for the ISO15156/NACE MRO175 specification has been successfully completed

Text by the International Titanium Association

The project involved a several years-long effort to source sample materials and conduct NACRE required autoclave testing to prove resistance to corrosion and cracking in sour service environments found in crude oil and gas production units.
The IAC pointed out that although the testing was completed more than three years ago, the publication of the Technical Circular with the updated specification requirements was only published this last month, having been delayed by the global pandemic and the combinate of NACE with the Society for Protective Coatings.
The updated requirements for the application of titanium Grade 12 to ISO 15156 petroleum and natural gas industries for industrial materials for use in H2S-containing environments in oil and gas production is an important development as it brings the specification requirements into harmony with current mill practice.
The historical requirements for Grade 12 were based on a specific batch anneal cycle and the major titanium producers were not able to certify to this restrictive batch anneal requirement. The testing program undertaken by the IAC demonstrated that a continuously annealed product was equally resistant to sour service environment as the batch annealed product. This update to the specification will allow titanium mills to certify materials in compliance with ISO15156 without taking exception to the anneal requirements.
In addition, the IAC was able to remove a restrictive maximum hardness requirement from the specification. The committee maintained that hardness test results are not a reliable indicator of strength in titanium alloys and hardness does not correlate directly with susceptibility for corrosion. Grade 12, in the annealed condition and satisfying the UNS R53400 chemistry requirements, is now acceptable per the new standard requirements.
It’s expected that updating requirements for titanium Grade 12 will open up significant new business opportunities for the titanium alloy. The ITA congratulated Rob Henson, the chair of the IAC and the manager, business development, for VSMPO Tirus US, and Chris Wilson, technical director, Uniti Titanium, for “their tireless efforts to finalize this important specification update.”
Grade 12 is a titanium alloy that contains molybdenum and nickel and is highly resistant to hydrogen-sulfide industrial production environments, with demand coming from industries such as oil and gas, chemical processing wastewater treatment and mining projects. Applications for titanium Grade 12 in oil and gas production would include pressure vessels, valves, pipes, fittings and heat exchangers. Such components, under MRO 175, must be certified to resist “catastrophic cracking” and failure when operating in a corrosive hydrogen sulfide environment. The MRO 175 standard addresses an industrial material’s ability to withstand stress cracking in a hydrogen sulfide environment, also known as a “sour service” or “sour gas environment”. It’s important to note that since the start of this Grade 12 project, NACE International and SSPC, the Society for Protective Coatings, have merged to form the Association for Materials Protection and Performance (AMPP), a new association to serve the global corrosion and coatings industry which represents more than 37,000 members is over 140 countries.
This new association will not affect existing NACE or SSPC standards, including the NACE MRO 175/ISO 15156 standard. All existing standards that bear the NACE or SSPC name will continue to be used without change. Any new standards developed following the merger will bear the AMPP name.