Material Science & Engineering
Stainless
Steel
September 24, 2020
Andreza, Bangeles
What is Stainless Steel?
▪ It is an iron-based alloy known for
their corrosion and heat resistance.
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Properties
▪ Higher corrosion resistance
▪ stainless steels are iron-based alloys that contain a
minimum of around 10.5% chromium
▪ Attractive Appearance
▪ Temperature resistant
▪ High Tensile Strength
▪ Easy formability and fabrication
▪ Low Maintenance
▪ Environmentally Friendly
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Stainless Steel
Classifications
Let’s dive in
Austenitic
▪ nickel improves corrosion resistance and makes
stainless steel more ductile.
▪ molybdenum further enhances the resistance to
corrosion
▪ These modifications can make the steel suited to
high temperature applications
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Austenitic
▪ The most common grades are Type 304 and 316
▪ Applications
▪ kitchen equipment, cutlery, food processing
equipment, and structural components in the
automotive and aerospace industries.
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Ferritic
▪ Ferritic steels are the 400 Grade stainless steels
noted for their high chromium content, which can
range from 10.5% to 27%.
▪ It offers good ductility, tensile-property stability, and
resistance to corrosion, thermal fatigue, and stresscorrosion cracking
▪ It is magnetic and a good resistant
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Ferritic
▪ Applications
▪ Vehicle exhausts, Fuel lines, Cooking utensils,
Architectural trim, Domestic appliances
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Martensitic
▪ These steels are like ferritic steels in being based on
Chromium but have higher Carbon levels up to as
high as 1%.
▪ This allows them to be hardened and tempered
much like carbon and low- alloy steels
▪ They are used where high strength and moderate
corrosion resistance is required.
▪ Low weldability
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Martensitic
▪ Applications
▪ wide range of parts and components; from compressor blades
and turbine parts, kitchen utensils, fasteners, pump and valve
parts, dental and surgical instruments, to electric motors,
pumps, valves, sharp surgical instruments, cutlery, knife blades,
and other cutting hand tools.
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Duplex
▪ 50% ferritic and 50% austenitic (approximately)
▪ It offer excellent quality, because of their low nickel
content
▪ weldable but need care in selection of welding
consumables and heat input.
▪ They have moderate formability.
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Duplex
▪ Application
▪ Heat exchangers, Marine applications, Desalination
plants, Food pickling plants, Off-shore oil & gas
installations, Chemical & petrochemical plant
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Precipitation Hardening (PH)
▪ adding elements such as Copper, Niobium and
Aluminum to the steel develops strength
▪ can be machined to quite intricate shapes requiring
good tolerances.
▪ Application
▪ Pulp and paper industry equipment, Aerospace
applications ,Turbine blades, Nuclear waste casks,
Mechanical components
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Disadvantage
• Costly
• Stainless steel is difficult to use in
welding
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Stainless Steel Market
▪ Energy and Industry
▪ Household Appliances & Catering
▪ Architecture Building & Construction
▪ Automotive & Transport
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References
▪
https://www.aperam.com/what-stainlesssteel#:~:text=Stainless%20steels%20are%20steels%20containi
ng,carbon%20and%20other%20alloying%20elements.&text=S
tainless%20steel's%20corrosion%20resistance%20and,%2C%2
0niobium%2C%20manganese%2C%20etc.
▪
https://nickelinstitute.org/media/1783/roleofstainlesssteelsini
ndustrialheatexchangers_9005_.pdf
▪
https://www.sherwoodsteelinc.com/strengths-weaknessesstainless-steel/
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