Heather Allain, Executive Director, Materials Technology Institute (MTI), tells us about her passion for materials and the importance of MTI’s work to provide awareness of safe, reliable and sustainable materials use.
World Food Safety Day on 7 June 2023 draws attention to food standards. Foodborne diseases affect 1 in 10 people worldwide each year, and food standards help us to ensure what we eat is safe.
Materials selection for any piece of equipment or a process system is rarely a simple task, unless you are exactly replicating something successful. Often engineers will have a checklist to help them narrow down the choices, eliminating groups of materials that are not suitable for various reasons. Austenitic 300 series stainless steels containing 7-35% nickel will have most if not all of the boxes checked for being suitable where a stainless steel is desired.
The sudden failure of a building or bridge is mercifully a rare event, thanks largely to international or national standards: structures are designed in accordance with a design standard, using products conforming to a product standard and manufactured using techniques and to a quality level defined in a construction standard.
Each family of stainless steels has its strengths and weaknesses. Ferritic stainless steels have useful properties – a lower rate of thermal expansion, higher thermal conductivity, strong ferromagnetism and very high resistance to chloride stress corrosion cracking (SCC). When looking at selecting any alloys, it is important to consider all the factors for successful usage.
The duplex alloys are “problem-solving alloys” for good reason, they have been successfully used in many places where carbon steels and standard austenitic alloys have failed. Just like with the austenitic family, there are many different duplex alloys to choose from, with corrosion resistance varying from moderate with the lean duplex alloys to very high with the superduplex alloys.
The selection of an alloy should be guided by careful examination of the needs of the application. Before making a switch, it’s important to fully investigate an alloy’s strengths, weaknesses and applicability to your structure.
Think of the largest cruise ship. Then imagine how much it weighs – just over 100,000 tonnes, in fact. Now think about 500 of those ships, and what they weigh. That is the staggering amount of new electronic waste that we generate every year.
Even small quantities of nickel in an application can make a big difference to successful deployment.