Stainless Steel World Americas Journal August 2023 | Page 11

Training Article

Figure 4 : Selecting and specifying the right materials are complex questions , as the answers depend on a variety of associated factors , including environmental conditions , required performance , and cost .
Each situation demands its own evaluation , and factors like environmental conditions , required performance , and cost should be considered . Though operators often like to use one material throughout the platform , it may not be economical to do so .
After all , 316 stainless steel offers good ductility , which allows for easier forming and welding at a lower price point . For many oil & gas fluid systems , 316 stainless steel remains the top choice , particularly if they are shielded from external factors like sun and salt spray . It is , however , important to understand that not all 316 stainless steel formulations are created equal . Some have higher concentrations of nickel and chromium than are required by ASTM , which means they are less susceptible to corrosion and are more reliable .
Alternatives
In contrast , fluid systems that handle sour gas require much more significant corrosion protection . Such systems are more likely to suffer from sour gas cracking or sulfide stress cracking ( SSC ), Figure 6 . SSC occurs when the metal corrodes through contact with hydrogen sulfide and moisture , which is common on offshore platforms and is becoming a more significant problem as sour reservoirs are developed worldwide .
Under such conditions , metal becomes brittle , and cracks more frequently as
Figure 5 : 316 stainless steel forms a passive , chromium-rich oxide layer on the surface to protect it from corrosion naturally ( top ). When this outer layer is damaged ( middle ), it naturally reforms ( bottom ).
tensile stress and corrosion combine . That is why more advanced alloys like Alloy 825 , Alloy 625 , and others should be used in such conditions to ensure the system ’ s safety and durability . These requirements are specified by the NACE MR0175 / ISO 15156 standard .
In between the two extremes , other opportunities exist to use specific metals that best align with the goals of an application . In some systems , for example , advanced alloys may only be necessary for tubing , while 316 stainless steel can be used for tube fittings . If oil & gas professionals have a more complete understanding of the science behind specifying these materials , they can make smarter decisions about what alloys will improve the safety of their platform while maintaining profitability .
How Materials Science Training Can Help
To ensure oil & gas operators receive the right training in metallurgy and materials science , it is important to choose programs that employ trainers with real-world experience and who have been thoroughly trained themselves .
The right training program addresses the specific challenges the facility faces , instead of instead of using general knowledge and understanding . Trainers should also be intimately familiar with local circumstances , regulations , and other geographic-specific situations that inform the facility ’ s particular needs , Figure 7 . For example , there are different regulations for oil & gas activity in the Gulf of Mexico than those in the northern United Kingdom . A trainer should understand the difference .
Another important factor of evaluating a training program is how well trainers understand the local workforce . The more trainers understand what knowledge is necessary for specific workers , the better they can connect with their training needs . For example , in some areas of the world , workers need more materials science and corrosion training , and the workers are particularly receptive to receiving it . In those instances , trainers can tailor metallurgy and materials science training to improve their overall knowledge and take it to higher levels .
In the case of oil & gas professionals , trainers should also be able to address the specific alloys used in the applications . Understanding the needs of oil
and gas problems is crucial because the conditions on any platform can affect materials selection . For example , it is important to understand how most tubing and fittings are installed , how systems are kept clean , or whether they can be protected from outside irritants .
Final Thoughts
Reliable suppliers should be able to have in-depth conversations with a team leader to decide what kind of materials science training the team needs . They should also be able to guide them in their selection of materials that will meet the needs of the platform applications .
In the end , choose trainers who can be as local as possible , so they understand the conditions , markets , and needs of the team . Such training will elevate the performance of the platform and improve safety and profitability for years to come .
About the Author
Joel Martin is a Manager , Marketing Training & Services for Swagelok Company .
Figure 6 : When dealing with a fluid system that handles sour gas , sulfide stress cracking ( SSC ) is common . It is the result of exposure to hydrogen sulfide and moisture .
Figure 7 : When deciding on materials science training modules , make sure the trainer is familiar with local and regional regulations , or local geographic factors so they can address your specific needs .
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