Hi and welcome to Metal Supermarkets, the Convenience Stores for Metal.
I'm Jason Jackson, Operations and Development Manager.
In this video blog series, we've been looking at the four main types of steel
using our acronym C.A.S.T.
which stands for carbon steel
alloy steel
stainless steel and tool steel.
We've already talked about how steel is classified
and looked closer into the first two types of steel from our acronym.
Today we'll take a closer look at the "S"
Stainless steel
Stainless steel typically contains between 10% and 20% chromium.
It is the main alloying element and helps to make stainless steel extremely corrosion resistant.
In fact, stainless steel is about 200 times more resistant to corrosion than mild steel.
Stainless steel can be divided into five groups:
Austenitic
Ferritic
Martensitic
Duplex
and Precipitation Hardening
Austenitic steels make up the largest portion of the global stainless steel market
and have a wide range of applications such as
food processing equipment, kitchen utensils, medical equipment and more
Austenitic stainless steel grades are
weldable, non-magnetic and not heat treatable.
Typically, Austinitc stainless steels can be loosely divided into three groups
Common chromium nickel which is the 300 series,
Manganese chromium nickel nitrogen which is the 200 series
and specialty alloys.
Ferritic steals contain trace amounts of nickel,
between 12% and 17% chromium, less than 0.1% carbon,
and other alloying elements such as molybdenum, aluminum or titanium.
Ferritic steels tend to have good ductility and formability
but relatively poor high temperature strengths when compared to Austenitic grades.
Ferritic stainless steels are magnetic but not heat treatable
and often cost less than other stainless steels.
Some Ferritic grades include 405 and 409
Martensitic steels contain 11%  to 17% chromium,
less than 0.4% nickel and up to 1.2% carbon.
The higher carbon content of this heat treatable steel affects forming and welding.
To obtain other useful properties and prevent cracking preheating and post weld heat treatment is required
Martensitic stainless steels such as 403, 410, 410-Nickel Molybdenum
and 420 are magnetic and heat treatable.
They are often used for dental and surgical equipment knives and other cutting tools.
Duplex steels typically contain 20% to 25% chromium and 5% nickel, along with molybdenum and nitrogen
Duplex steels have higher yield strength and greater stress corrosion cracking to chloride
than Austenitic stainless steels.
Some applications include chemical plants and piping.
Precipitation hardening steels are chromium nickel stainless steels
that also contain alloying elements such as aluminum copper or titanium.
These alloys allow the steel to be hardened by a solution and aging heat treatment.
They can be there Austenitic or Martensitic in the aged condition.
Hopefully this has given you a better idea of common types of stainless steel.
Stay tuned for the final part of this video blog series
where we will look closer at the last letter in our acronym C.A.S.T.
Tool steel.
If you need stainless steel for your next project
Metal Supermarkets is the world's largest supplier of small quantity metals.
carrying over 8,000 types, shapes and grades of metal
including various stainless steel grades
cut to size and ready fast!
