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Duplex
Growth rates How fast is the duplex stainless-steel sector growing , and what is its market share compared with other stainlesssteel types ? The answers to both questions depend on whom you ask , but , in terms of absolute growth , the answer is clear : the demand for duplex is stronger than it ever has been and will increase even more in future years . Data Bridge Market Research cautiously projects a CAGR of 3.2 % between 2022 and 2030 , whereas Research Nester more optimistically forecasts a CAGR of over around 7.7 % from 2023 to 2035 , with revenue more than doubling over the period ( 1 ) . Forecasting demand rests on certain assumptions about the growth rate of the various markets . The main driver of demand is generally agreed to be oil & gas , especially offshore , so the projected increase in demand depends on how much growth is expected from this sector , a crucial question given the need to curb CO 2 emissions and transition to green energy . That said , duplex finds many uses in solar and wind energy , and in biogas pants , which often require highly corrosion resistant tanks . Moreover , the demand from architecture & construction , especially in the Asia Pacific region , and from a wide range of other industries including petrochemical , paper & pulp , and desalination , inclines one to be optimistic about future demand for duplex . As for the growth of duplex compared with other stainless-steel types , the more optimistic projection of 7.7 % for duplex is slightly above the average for all stainless-steel types combined ( CAGR growth projections for stainless steel market size vary from 6.8 % between 2023 and 2029 and 5.5 % from 2023 to 2033 .) ( 2 ) . This would suggest that duplex has a slight edge over other stainless types , including austenitics ( which one market report projects to grow 6.2 % between 2023 and 2029 ) ( 3 ) . To this we may add anecdotal evidence suggesting duplex is gaining over austenitics : one often reads that , at the beginning of a project , end users expect to apply an austenitic grade but are later persuaded by a supplier to use a duplex grade instead . For instance , when the City of Barcelona planned to build stainless steel tram shelters , they specified type 316 in the tender but ended up applying Stalatube ’ s LDX 1.4162 .
The City of Barcelona built 22 tram shelters , for which Stalatube ’ s high-strength LDX 1.4162 lean duplex was used , instead of the 316 austenitic grade mentioned in the invitation for tenders .
Advantages The per-weight price of a duplex grade may exceed that of austenitics , but its strength allows reductions in weight and bulk that more than compensate . The lighter structure and thinner walls make transportation and installation easier . Weight savings are an important consideration on oil platforms , for instance on walkways where salt corrosion occurs . Outokumpu has claimed that applying duplex to replace Hot-Dipped Galvanized ( HDG ) steel for walkway gratings in marine environments could enable weight reductions of up to 40 % ( 4 ) . Duplex combines super corrosion resistance with erosion resistance , making it very suitable for applications where solids or slurry are being handled ( wastewater treatment , pulp & paper , desalination ). Superior corrosion resistance makes the
Working with duplex
Choosing a duplex grade instead of an austenitic one can be risky if you do not know how to work with these materials , as they are harder and stronger . Fortunately , there is no lack of advice on-line to learn the distinctive but not very difficult art of working and welding duplex . One of the more recent guides is downloadable at : https :// stalatube . com / 2021 / 09 / 03 / lean-duplexblog-series-2-working-with-duplex-stainless-steel . Downloadable brochures are provided by the Nickel Institute , “ Practical guide to using duplex stainless steels ”, 2 nd edn , 2020 ), ArcelorMittal (“ Duplex stainless steels welding guidelines ”, 2019 ), and the International Molybdenum Association (“ Practical guidelines for the fabrication of duplex stainless steels ”, 3 rd edn , 2014 ).
A biogas plant in Japan , equipped with a 450-kW cogeneration power pant , with tanks constructed in duplex grades 1.4062 , 1.4162 in the lower rings , and 1.4462 for the top rings which are in contact with the biogas . Photo by Weltec Biopower . www . heat-exchanger-world . com Heat Exchanger World April 2024
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