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The chemical
process industry requires duplex stainless steels in a wide
spectrum of corrosive conditions. In particular corrosion
problems in processes with elevated temperatures and chloride
conditions can be solved by the application of duplex. Typical
examples are PVC stripper columns and heat exchangers, pressure
vessel for organic products, reactors for the oxo alcohol
production, sulphuric acid applications and phosphoric acid
production. Below you will find an overview paper on the application
of duplex stainless steel in the chemical process industry
and a paper describing experiences with a superduplex grade
in the petrochemical, chemical and fertiliser industries.
The following articles are generally available through the
trade press, we regret we cannot supply them in their through
our site.
Application
of duplex stainless steel in the chemical process industry
Author:Giel
Notten,Managing Senior Corrosion Engineer, DSM Engineering
Stamicarbon, The Netherlands. Originally presented at the
97 Duplex Conference in Maastricht, the Netherlands, paper
D97-201.
Abstract
The use
of duplex stainless steels in the chemical process industry
has expanded rapidly over the past few years. They are now
used not only in chloride environments, where they are more
resistant to SCC than austenitic stainless steels, but also
in a wide variety of other demanding applications.
In DSM plants, duplex is used especially for chloride-containing
process fluids and for ammonium carbamate solutions. The material
has been found to offer good resistance to chloride SCC, although
such corrosion can and does occur at pH values lower than
3 to 4. This we established both in the field and through
CERT (constant extension rate testing). In a strongly alkaline
chloride-bearing solution, duplex SS gives excellent performance
whilst a high-nickel alloy fails after about three years because
of SCC. These findings are supported by drop evaporation tests.
Duplex
stainless steels in refinery and petrochemcal heat exchanger
applications
Martin
Holmquist, AB Sandvik Steel, Sweden
Abstract
Duplex
stainless steels (DSS) are today used in a variety of applications
within the refining- and petrochemical industry. In this paper
some examples on typical use of DSS heat exchangers are given.
Some important material properties are being discussed as
well as fabrication aspects, such as tube-to-tubesheet joining.
Application examples are given from distillation, hydrotreating
and waste water treatment in the oil refinery and from production
of organic acids and chlorinated hydrocarbons in petrochemical
industry. Besides the corrosive process fluids, chloride containing
cooling waters are common in the hydrocarbon processing plants
and use of the duplex grades under such conditions is also
discussed.
Experiences
with Zeron 100 super duplex stainless steel in the process
industries
Authors:
R. Francis, G Byrne, G.R. Warburton, Weir Materials &
Foundries, Manchester, UK,originally presented at the Stainless
Steel World 99 Conference, the Hague, The Netherlands, paper
number SSW99-007.
Abstract
The process
industries have used 300 series stainless steels for many
years where the corrosion resistance of carbon steel is inadequate.
Where stainless steels have proved inadequate there has been
a tendency to utilise high nickel alloys with a greatly increased
cost. This paper introduces Zeron 100 super duplex stainless
steel and shows how its superior corrosion and stress corrosion
cracking resistance, plus its high strength, can be utilised
to provide a cost effective alternative to both austenitic
stainless steels and high nickel alloys. The composition,
mechanical properties and corrosion resistance are discussed
showing that the combination of high strength and excellent
corrosion resistance make it eminently suitable for a wide
range of industrial applications. The paper reviews examples
of the applications of Zeron 100 including service experience
in the petrochemical, chemical, fertiliser and mining industries.
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