6 |
Polluted water from steel plants |
Chlorides ≤ 500mg / L , PH = 7.5 – 8 , 100 ° C |
Service life 5 years and still in use . |
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less ductile – super-duplex grade SDX 2507 to serve as an alternative to more expensive super-austenitic and titanium alloys . The aim of this work was to achieve a more cost-effective solution with less intensively formed heat-exchanger plate designs , which benefitted because of its leaner alloying composition , higher strength , and comparable corrosion resistance . This work has resulted in the consistent production of welded PHE using SDX 2507 . Until now , both DX 2205 and SDX 2507 were widely used for PHEs in industries , such as in oil refining , the chemical and pharmaceutical industries , for environmental protection , in nonferrous metal industries , and in wastewater treatment . This is an impressive achievement by LANPEC and Prof . Chang , which clearly moves the boundaries forwards as to what type of applications duplex stainless steel can be used for . In Table 2 a few different cases and their critical environments are highlighted in which either DX 2205 or SDX 2507 were selected .
Conclusions on the suitability of using duplex stainless steels for PHE
• Higher design stresses can be tolerated than for austenitics – allowing for higher working pressure or thinner plates .
• Relatively complex flow patterns can be pressed using similar forming tools as for austenitics supported by material supplier expertise .
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• Cost-effective solutions can be realized utilizing their superior properties to improve the performance of the heat exchanger . The leaner alloying composition provides a higher relative corrosion resistance , which delivers reliable operations and potentially longer service life , hence a lower total LCC .
Reference [ 1 ] Sheet Metal Forming Handbook , Outokumpu 2017 .
About Outokumpu
Outokumpu is the global leader in sustainable stainless steel . Our stainless steel has the highest recycled content and the smallest environmental footprint in the industry . The company is organized into four business areas – Europe , Americas , Ferrochrome and Long Products . We employ some 10,000 professionals in more than 30 countries , with the headquarters in Helsinki , Finland . The history goes back to the invention of stainless steel and we continue to drive stainless steel innovation . Outokumpu offers today the widest portfolio of high performance stainless steels products in the market .
About the authors
Claes Tigerstrand - Head of Heavy Industry , Technical Value Creation , BA Europe , based in Sweden with more than 20 years ’ experience of global technical marketing related to stainless steel for Outokumpu .
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