Typical Types of Steels
Depending upon the processing route, many different grades of steels can be created. These can have impacts on the microstructures, hardenability and subsequent uses. The video below touches on some of the impacts that the processing can have due to cooling.
These different types of steels can be etched with a variety of acids to show the grain structure and other phases in the steel. Some of which can be spectacular.
Very Low Carbon Steels
These types of steels are normally very ductile, they are easy to press.
Examples of Applications for very low carbon steels include Car Bodies, White Goods and Steel Cans.
Steel Cans and Automotive Bodies are very demanding products requiring tight control on alloying elements to enable their demanding forming methods.
Low Carbon steels.
When the carbon level increases, strength increases however ductility decreases. This higher strength and thicker steel is used in the wheel and banding steel markets.
Aluminium is being used to directly compete with the automotive wheel market.
Further increases in carbon, alongside increases in Manganese and Niobium.
Marine steels are very demanding, with very high strength steels required for the armour plating.
Cargo ships are less demanding than warships, such as the Type-45 destroyer developed by the UK, however lightweighting is being looked into using more alloyed steels to reduce the overall weight and thus carbon footprint of the vessels. The Cruise ship market is highly competetive, with Aluminium also being used as a competitor for alloyed steels for lightweighting. New grades of steels are constantly being developed to improve the cost/weight performance to meet customer requirements.
Steels for the Chemical Industry
Depending upon the role of the steel, very different elements will be used to meet the customer requirement.
Pressure vessels for high temperature applications, for example, require chromium and molybdenum additions to impart the desired strength and cooling temperature requirements.
In the construction industry, wear and abrasion resistance are commonly required, such as for a front loading shovel below
This tends to lead to usage of chromium, titanium, molybdenum and boron. However in different ratios than other types of steel mentioned previously
There are many different types of rail steels, this is due to the volume of potential applications. These include, but are not limited to:
These will be discussed further in Steel for Transport topic. However they have a multitude of abrasion performance, formability and environmental conditions, such as coastal and temperature) which all add to the challenge.
Stainless Steels are a broad family of chromium rich steels. There are many different groups within it, however the two major are StainLESS and StainFREE. Stainless Steels stain under specific conditions.
To be classed as "Stainless" a steel has to have greater than 12% Chromium. Often this will be in combination with a variety of other alloying elements, such as Nickel. This family of steels is expensive as the alloying elements used are not cheap, such as Chromium, Nickel, Molybdenum and Tungsten.
Austenitic Stainless Steels are a very important group, in which they have very good low temperature properties down to -100 degrees Celcius. This makes them key for the transport and storage of chemicals, liquefied gasses and even some types of whiskey.