What is Alloy Steel | Types, Properties, Applications & Grades

by AMC

Posted on January 24, 2023 at 13:40 PM

 what is alloy steel - Amardeep Steel

What Is Alloy Steel?

Alloy steel is made by combining a number of different elements, such as silicon, chromium, molybdenum, boron, vanadium, nickel, aluminum, etc. These alloying elements make the alloy steel stronger, tougher, harder, and more resistant to wear. Some of the elements that can be added to an alloy and what they do are shown below.

Common Steel Alloying Elements

When it comes to steel, a lot of different things can be added to the base material, which lets the buyer change things until the right alloy is found. Some common elements that are used to make alloys are:

  • Manganese: When small amounts of sulphur and phosphorus are added to it, manganese makes the steel alloy less brittle and easier to hammer.
  • Chromium: A small amount (0.5% to 2%) can help make the alloy harder, and a larger amount (4% to 18%) can also stop corrosion.
  • Vanadium: Just 0.15% of this element is enough to improve strength, heat resistance, and the structure of the grain as a whole. When chromium is added to the steel alloy, it makes it much harder but keeps its ability to be shaped.
  • Nickel: Up to 5% of this alloying element, will make steel stronger. It has a corrosion resistance that is very good at more than 12%.
  • Tungsten: Increases resistance to heat, which makes the melting point higher. It also improves the way the steel is put together.

Types of Alloy Steel

Alloy steel is made by mixing steel with a number of other elements to give it new properties and traits. It is divided into two types based on how much of each element is used to make the alloy steel, which can be anywhere from 1% to 50%. Two groups of alloy steel will be mentioned in the flow.

High-Alloy Steel: It has a lot of elements that make it stronger. Most high alloy steel is stainless steel, which can have as much as 12% chromium in it. The latent layer is a thin layer of oxide that chromium makes on the outside of the steel. The high amount of chromium protects against erosion for a long time. This alloy is a bit more expensive than low alloy steel. Because of this, it is mostly used in cars and industrial machinery.

Low-Alloy Steel: It has between 1 and 5 percent of alloying elements, which is less than high-alloy steel. Depending on the alloy, this steel has different strengths and can be used for different things. Also, this type of alloy is used in large flanges to get certain mechanical properties. So, low alloy steel can be used for a wide range of projects in many different industries, such as making studding outlets and seamless rolled rings.

Tip : You can read our in-depth Blog about the - Difference Between High Alloy Steel and Low Alloy Steel

Alloy Steel Properties

Element Symbol wt. % Function
Aluminium Al 0.95–1.30 Alloying element in nitriding steels
Bismuth Bi Improves machinability
Boron B 0.001–0.003 Improves hardenability
Chromium Cr 0.5–2.0 Improves hardenability
4–18 Corrosion resistance
Copper Cu 0.1–0.4 Corrosion resistance
Lead Pb Improves machinability
Manganese Mn 0.25–0.40 Prevents brittleness in combination with sulfur
>1 Increase hardenability
Molybdenum Mo 0.2–0.5 Inhibits grain growth
Nickel Ni 2–5 12–20 Increases toughness Improves corrosion resistance
Silicon Si 0.2–0.7 Increases strength and hardenability
2 Increases yield strength (spring steel)
Higher % Increases magnetic properties
Sulfur S 0.08–0.15 Improves machinability (free-machining steel properties)
Titanium Ti Reduces martensitic hardness in Cr steels
Tungsten W Increases hardness at high temperatures
Vanadium V 0.15 Increases strength while maintaining ductility, promotes fine grain structure

Tip: You can read our in-depth Blog about the -Properties & Uses of Alloy Steel

What is the Alloy Steel Used for?

Different kinds of alloy steel can be used to make a huge number of different things. There are alloy steel pipes and tubes, alloy steel plates, sheets, and coils, alloy steel bars, rods, and wires, alloy steel forged fittings, alloy steel buttweld fittings, alloy steel flanges, fasteners, and more. Alloy steels are used in many different industries, like cars, mining, machinery and equipment, railroads, road building, buildings, appliances, and even off-shore applications.

Applications in Building Large Structures
In the building and construction industry, steel skeletons made of alloy steels are used for very large modern structures like airports, bridges, skyscrapers, and stadiums. Alloy steels have the high strength needed to hold up such big buildings. Even structures made of concrete use alloy steels as reinforcements to make the structures stronger and lighter. Alloy steel is also used to make small things like screws, nails, and bolts.

Applications in Building Bridges
Weathering steels, which are a type of alloy steel, are used to make bridges. Because nickel, copper, and chromium are used as alloying elements, these offer better protection against corrosion. Weathering steels are also used on the outside of buildings to make them look better. Weathering steel has a lot of benefits, such as high safety, easy and quick construction, good looks, shallow depth, low maintenance, and the ability to be changed in the future. Due to the way it naturally ages, it doesn't need to be painted, so it doesn't cause environmental problems like paint does. In the long run, weathering steels saves a lot of money.

Alloy Steel Flat Products
Alloy steels are used to make plates and strips, which are flat items. There are many different grades and sizes of plates. By welding plates together, these are made into sections that are used in building.

Alloy Steel Strip and Coil Products
Strips can be rolled hot or cold, and they can also be galvanized by being dipped in hot water. Hot-dipped galvanized coils are used to make building materials like wall and roof claddings, side rails, roof purlins, light steel frames, and lintels.

Alloy Steel Long Products
Alloy steels are used to make long products like girders, structural sections, bars, rails, rods, and wires that are used in the building industry.

Alloy Steel Flanges
Flanges made of alloy steel are used to make another important thing. These are used in pipes made of stainless steel. These flanges can be made in different ways to fit different needs. Some of them are weld neck flanges, which have the same thickness and bevel as the pipe and can work well in harsh conditions like high pressure, high temperature, or temperatures below zero. Lap joint flanges are slip-on flanges that can be used with alloy steel pipes that need to be checked and maintained regularly.

Alloy Steel Pipe Products
Alloy steel pipes are an important part of the building and construction industry because they are flexible, easy to fix without heat treatment, and last a long time. They are made of a mix of nickel, chromium, and stainless steel. Large-diameter welded pipes, electric fusion welded pipes, welded pipes, and seamless pipes are some of the special kinds of alloy steel pipes. In addition to high-pressure situations, they are also very useful in high-temperature or corrosive situations.

What Grade is Alloy Steel?

Chrome Molybdenum Steel
Overview We supply chromium molybdenum steel, chromium molybdenum nickel steel and chromium molybdenum tungsten steel to various engineering, power generation, oil & gas, petrochemical, welded tube fitting and nuclear industries. Our facilities enable us to cater to the specific requirement of the customers.
Application Boiler Pressure Vessels, Tube & Pipe fittings, refinery equipments for elevated temperature service.
Grades ASTM A387 Grade 11/ 12/ 22/ 5/ 9/ 91, EN 10028 -2 / DIN 17175 , ASTM A204 / A302, SAE 4130 / 4140 / 8620, EN 19 / EN 24 / EN 36
Supply Condition Normalized & Tempered / Annealed / Normalized.
Abrasion / Wear Resistant Steel
Overview The hardened boron steel is extremely resistant to abrasive wear and high surface pressure. The excellent mechanical properties of boron steels are achieved through heat treatment. It also offers good weldability with cold bending properties.
Application Wherever demands are imposed on abrasion resistance e.g. dump trucks, excavators, loaders, chutes, conveyors, feeders etc.
Grades 500HB / 400HB / 300HB / 200HB
Supply Condition Quenched & Tempered(If required)
Quenched and Tempered Steel
Overview Quenched and tempered fine grained steel is used for welded steel structures having demands of low weight and high load.
Application Pressure vessels, penstocks, bridges, transport vehicles, cranes, frameworks, conveying plants etc.
Grades EN 10025-6-S500 / S550 / S620 / S690
Supply Condition Quenched and Tempered
High Tensile Steel
Overview The structural steel with high tensile properties is used for general construction so as to reduce the section weight.
Application Fabrication, Engineering construction
Grades EN 10025-2-S355 / S420 / S460. IS 2062 E350/ E410 / E450
Supply Condition Normalised / Normalised Rolled
Corrosion Resistant Steel
Overview It exhibits increased resistance to atmospheric corrosion compared to unalloyed steel as it forms and regenerates a protective layer under the influence of the weather.
Application Steel frame structures, bridges, tanks, containers, exhaust systems etc.
Grades ASTM A588 / A242. IRSM - 41
Supply Condition Normalised Rolled / Normalised
Tool Steel
Overview Hot & Cold work tool steels as per the Standard (A681) as well as customer requirement is produced based on design application, service condition and desired properties.
Application Tools, Dies & Fixtures
Grades A2 / H11 / O1 / D2 / D3/ S-13 / HCHCR
Supply Condition Spherodise Annealed
Pressure Vessel Steels
Overview This Carbon steel plates are intended for welded pressure vessels, iron sturctures where improve notch toughness is important.
Application Pressure Vessel Boiler, Tube Fittings
Grades ASTM A516 / A515. ASTM A537 CL.1 & CL.2
Supply Condition Normalised / Normalise Rolled/ Quenched & Tempered
Other Alloy Steels
Overview The various special steels having diverse applications are produced as per customer requirement.
Application Automobile, Valves, Bearing, Extruders, Springs
Grades 16/20MnCr5,EN52, EN1A,EN41, EN31,56Si7,42CrMo4
Supply Condition As Rolled / Annealed / Normalised / Quenched & Tempered

What are the advantages of alloy steel?

Whether your project needs advanced corrosion resistance, the ability to be machined, strength, or a number of other features, there is an alloy steel that has what you need. With some extra heat treatment, alloy steels can have a lot of good qualities, such as:

  1. Improved resistance to corrosion
  2. Increased ability to get harder
  3. Stronger and harder than most
  4. Unique alloyed features

Does Alloy Steel get rusted?

First of all, it depends on if you mean "rust" or "corrode." Corrosion is a type of oxidation, while rusting is a type of corrosion. If a metal alloy has iron in it, it will rust. All alloys can corrode. When we expose metal to air and water, a layer of iron oxide forms on the surface. Corrosion happens when we put metals in the air or near chemicals. This makes metal oxides or salts form.

Find the Steel Alloy You Need

Searching for premium alloy steel products? Amardeep Steel stocks a wide selection of steel alloys in the shapes and sizes you need. We also provide metal cutting services to make purchasing easy and convenient. Get a steel alloy quote today.