Outokumpu Supra 316plus stainless steel reduces weight of LNG tank container by 30%

September 13, 2017
Source: ASM International

Outokumpu Oy, Finland, announces that Finnish liquefied natural gas tank manufacturer LNGTainer has launched a new tank that brings together two innovations – LNGTainer's game-changing tank container, and Outokumpu's unique austenitic stainless steel grade, Supra 316plus (EN 1.4420, UNS S31655).

"The most revolutionary aspect of LNGTainer's new tank container is that the structure includes a lightweight, flexible inside tank, and an outside pressure vessel," says LGTainer CEO Tom Sommardal. "For the lightweight inside tank, we chose Outokumpu's Supra 316plus steel grade. With the new patented structure, we could decrease the weight of the tank by 30% and increase its capacity by 15%. Because the weight of the inside tank is significantly less than in competing tanks, the time for cooling off the inside tank is considerably shorter. The lightweight inside tank cools off faster for transport."  

LNGTainer first considered aluminum for the inside tank, while Outokumpu offered Supra 316plus because of its properties. Supra 316plus has relatively better low-temperature properties compared to other similar materials. In fact, its strength and ductility only improve as the temperature drops down to the lowest measured cryogenic temperature of  −196°Celsius. LNG is transported at a temperature of −164°C, and then is warmed back to gas when delivered.

"By having excellent low temperature properties, Supra 316plus enables thinner gauges, which translates as savings in weight, fuel, and energy costs, as well as a lower carbon footprint. LNGTainer's new tank container is a real breakthrough, and it demonstrates the best use of stainless steel properties in extreme conditions," says Product Manager Juha Kela at Outokumpu.

Supra 316plus has a higher chromium and nitrogen content, and less nickel and molybdenum. Thanks to the optimized composition, the grade has good corrosion resistance and its performance is superior to conventional steel grades when the temperature drops down to cryogenic temperatures. In addition, the price of the grade is competitive and stable.




Subject Classifications

Industries and Applications | Boilers, Pressure Vessels, and Heat Exchangers

Industries and Applications | Fossil Fuel Power

Materials Properties and Performance | Corrosion

Materials Properties and Performance | Mechanical Properties

Metals and Alloys | Stainless Steels