LDX 2101 Economical suction roll shell material e LDX 2101 lean duplex stainless steel by Outokumpu Corporation is an economical material with properties matching the main requirements for suction roll shell applications. Valmet's process know-how as a paper machine builder and unrivalled experience in making suction rolls, combined with Outokumpu's world leading stainless steel expertise, have resulted in a functional suction roll shell. e main features are eﬃcient water removal, vibration free runnability, and long operational lifetime. ese shells are suitable both for new suction rolls as well as for shell replacements, regardless of the original roll supplier. Beneﬁts Optimal performance Durability due to high corrosion fatigue strength and good corrosion resistance Improved mechanical properties due to homogenous, ﬁne microstructure An economical choice for moderately loaded suction roll shell applications Unrivalled engineering expertise e smart choice for many suction roll shell applications Valmet's technical knowledge and long experience of making suction rolls are utilized in the shell dimensioning and engineering process. e excellent performance and long operational lifetime of the suction roll shell are ensured with detailed calculations, which take into account both the inuence of the corrosive environment and all the forces aﬀecting the shell. Valmet’s process know-how is utilized when selecting the optimal drilling pattern and open areas/hole volume for the suction roll shell. e goal is to maximize the dewatering capacity with minimized risk of suction hole shadow marking, prevent hole plugging and reduce roll noise level. Steel grade LDX 2101 Yield strenght Mpa 460 ksi 67 LDX 2101 is an economical low-alloyed austeniticferritic duplex stainless steel. Due to carefully optimized alloying it has the right material properties for durable suction roll shell operation: a high corrosion fatigue strength, needed in the cyclic loading conditions, and good corrosion resistance, giving protection against paper machine white water chemicals. is material can be used in moderately loaded suction roll shell applications. Tensile strenght Mpa 675 ksi 98 Corrosion fatigue 1) strenght Mpa 200 ksi 29 Pitting corrosion resistance equivalence PREN 26 * Typical value 2 1) Corrosion fatigue test in simulated whitewater testing environment (pH 3.5, Cl- 400 ppm, SO4 - 250 ppm, temp: approx. 20°C / 68°F) based on rotating four-point bending-method with 50% failure probability. Used frequency 5 Hz, no. of cycles 107. High-quality manufacturing methods Recrystallisation during the hot rolling process. © Valmet Corporation, SER33208 V2 EN 03/2014 Hot formed shell sections are welded together using high-quality welding methods developed specially for this purpose. e welding methods used and the subsequent controlled vertical heat treatment ensure consistent material properties for the plate material and weld areas. Good runnability is a critical issue for today's paper machines, which is why Valmet has set high tolerance and quality requirements for all shell manufacturing stages, starting from the rough turning of the shell blank and ending in the balancing of the nished shell. Shell holes are drilled using highly accurate precision drilling methods. Precision drilled holes have extremely high surface smoothness, helping to prevent fatigue crack initiation and hole plugging. For more information, contact your local Valmet oﬃce. www.valmet.com e-mail: [email protected], www.valmet.com/productvault Speci cations in this document are subject to change without notice. Product names in this publication are all trademarks of Valmet Corporation. Alloys with the best properties Corrosion resistance By courtesy of Outokumpu Prefab AB e shell blank is manufactured using continuously cast and hot rolled steel plates. During the hot rolling procedure the coarse microstructure common to cast steel is altered into a more homogenous and ne grain sized structure. e ner microstructure improves the steel strength properties, gives better resistance against heat cracking and also enables 100% ultrasonic inspection of the plates. Duplex stainless steels Austenitic stainless steels LDX 2101 Martensitic stainless steels Bronze Corrosion fatigue strength Latest roll cover technology Valmet also provides a versatile range of suction roll covers. ese include advanced polyurethane covers with superior wear and water resistance properties, hard coatings and a wide selection of rubber covers. Whatever the suction roll, we can provide a suitable roll cover to boost its performance to the maximum, without cover-speci c load or speed limitations.
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