To date one of the largest orders for tank building, 245 tons of Outokumpu lean duplex stainless steel was supplied for the construction of three big oil storage tanks at the Antwerp harbor in Belgium.
Ivens Construction takes care of the construction of the tanks. The company specializes in building and renovation of tanks for the storage of chemicals and fuels with 85 years of experience in construction with different types of materials.
“More and more duplex stainless steels are chosen because of the very good price-performance ratio. Duplexes have a similar corrosion resistance as the austenitic stainless steels which are normally used, but offer an advantage to optimize plate thickness due to higher strengths without diminishing the total tank integrity”, says Chief Technical Officer Jan Jochems from Ivens Construction.
The project sales manager at Outokumpu, Maarten Kimmel, agrees: “Forta LDX 2101 is a high potential steel grade for tank builders. Savings are achieved in structural weight due to thinness of the plates, and in welding thanks to 2-meter-wide coils, so less welding is required. In some cases initial investment costs are even lower than carbon steel coated tanks.”
Forta gives 20+ years to service life
The tanks in Antwerp are in service from September 2015. Their expected service life is 50 to 60 years compared to 30 to 40 years in the past. The longer lifetime is reached with the use of Outokumpu Forta LDX 2101 together with highly experienced quality of construction, and preventive maintenance and corrosion control during service.
Forta LDX 2101 makes the tanks virtually maintenance free and the strength of duplex stainless steel allows for material and fabrication cost savings and offers good corrosion resistance.
Weldability and the quality of welding play a crucial role in tank construction. “In terms of welding we have built up the experience to handle and perform the quality of the welds”, Jan Jochems says. He underlines that welding duplex is not more difficult but requires its own set of parameters as well as qualified and experienced welders.
The material of choice for long lasting tanks
Forta LDX 2101 lean duplex grade is developed and patented by Outokumpu and it has a low nickel content of only 1.5%. It can well compete in price with carbon steel tanks when the life cycle cost is taken into account. Forta LDX 2101 is increasingly becoming the material of choice also in the construction of storage tanks for pulp, chemicals, biofuels, beverages, grains, and ore slurry.