Duplex stainless steel is rapidly becoming the material of choice for pharmaceutical tanks. But why so? What makes this material perform so well? And what types of duplex stainless steel are available? With the help of Damstahl, we have put together this overview of duplex steel to mark the CPhI Worldwide pharmaceutical trade fair, which takes place in Milan from 9 to 11 November. Pharmaceutical experts from the translation service provider Norak will be attending the event, ensuring there will be no linguistic hiccups when it comes to orders for the manufacture of stainless steel pharmaceutical equipment.
Preparation tanks, storage tanks for ultrapure water, stainless steel process tanks or WFI tanks: Many different types of stainless-steel tanks and containers are used in the pharmaceutical industry. The one thing that they all have in common is the need for high-quality materials that meet the exacting demands of the pharmaceutical industry. However, high-quality, corrosion-resistant materials, especially the high-alloy stainless steel types typically used in the pharmaceutical industry, are expensive. Duplex steels offer a reasonably priced alternative and are increasingly used for stainless steel tank design.
Duplex stainless steel for chemical and pharmaceutical containers
The best of both worlds when manufacturing chemical and pharmaceutical stainless-steel containers: The term duplex steel refers to a very special group of stainless steels. The unique thing about duplex steels is that, unlike austenitic steels (e.g. the classic EN 1.4301 / AISI 304 and EN 1.4401 / AISI 316) or ferritic chromium steels (e.g. EN 1.4016 / AISI 430 and EN 1.4509 / AISI 441), they are not single-phase. Duplex steel is two-phase. To put it simply, this means that just over half (typically 55%) of the steel’s microstructure is ferritic, while the rest is austenitic. Duplex steel can therefore be described as a hybrid of the two most common groups of stainless steel. It is a crossover that is beneficial when manufacturing stainless steel process tanks for the chemical and pharmaceutical industries.
Duplex steel – the differences
As with the other main types of stainless steel, the duplex family comprises several grades of stainless steel. The term duplex steel without further qualification refers to the alloy EN 1.4462, which is characterised, among other things, by its high chromium content (21–23% Cr) and a molybdenum content (2.5–3.5%) that is slightly higher than for the acid-resistant austenitic family (at least 2% Mo). Both of these elements ensure excellent corrosion resistance. Duplex steel also has a low nickel content (4.0–6.0% Ni), which contributes to its relatively stable price. This combination of good corrosion resistance and reasonable price makes EN 1.4462 the workhorse of duplex steels. Grade EN 1.4462 accounts for around half of the duplex steels available on the market – which is also reflected in the manufacture of pharmaceutical stainless steel containers.
Super duplex – chemical and pharmaceutical tanks for critical situations
The name says it all: the super duplex family, typically containing 25% Cr, 7% Ni and 4–5% Mo, come into play whenever manufacturers of chemical and pharmaceutical stainless-steel containers demand absolute top quality. Super duplex is more resistant to corrosion than EN 1.4462 duplex steel and is most frequently used for critical components in the oil and chemical industries, and even in pharmaceutical tanks for critical processes. This is due to both its enhanced corrosion resistance and high mechanical strength.
Lean duplex – thin but strong pharmaceutical tanks
At the other end of the spectrum, we have the molybdenum-free lean duplex. Its corrosion-resistant properties really come into their own in environments with elevated temperatures, where standard austenitic steels show poor resistance to stress corrosion cracking. Lean duplex is used in the manufacture of stainless-steel process tanks for the pharmaceutical industry and for fastening elements, for example. Its advantages in terms of price are particularly evident when it comes to pharmaceutical stainless steel containers. Thanks to its high strength, the walls of tanks made from lean duplex can be thinner than for other stainless steel grades, resulting in significant cost savings. That’s why this type of stainless steel is increasingly used in the chemical and pharmaceutical industry.
Translations for the pharmaceutical industry
Contracts in the pharmaceutical industry do not just call for outstanding technical quality. As contracts for the manufacturing of pharmaceutical stainless equipment are often tendered and fulfilled internationally, linguistically flawless translations are essential. This is where the translation and localisation service provider Norak comes in. The Madrid-based company operates globally, and, with its network of over 4,000 translators, can translate your texts into 160 languages.
Norak is an expert in translations for the pharmaceutical industry. For exactly this reason, Norak has specifically established its Norak Pharma division, bringing together the combined pharmaceutical expertise of all its translators. The division is headed by Edward Davies, an expert with many years of experience in the pharmaceutical industry who originally comes from the UK.
The Pharma division is based in Prague, from where the team serves the relevant markets around the world. Read more about quality translations from Norak Pharma for manufacturing, helping you easily overcome linguistic barriers when manufacturing pharmaceutical tanks.
CPhI Worldwide – bringing together experts in the pharmaceutical industry
Visitors and exhibitors at the CPhI Worldwide trade fair, which will be held in Milan from 9 to 11 November, will have the opportunity to talk face-to-face with Norak Pharma experts. A team from the Pharma division is looking forward to meeting you there. Norak’s team of experts will be on hand to provide input and advice, especially when it comes to the industry-specific requirements for the manufacture of pharmaceutical and chemical containers and other pharmaceutical stainless-steel equipment.