Exploring Steel: Types, Properties & Applications

Steel is an alloy of carbon and iron. Due to its versatility, strength, and durability the steel used from construction and transportation to manufacturing and weaponry. The different steel types can be found in various grades, sizes, width, thickness making it suitable for different industries and applications.

Steel and It’s type

On Broader aspect there are 4 kind of steel which used majorly in India.

1. Carbon steel
2. Alloy steel
3. Stainless steel
4. Tool steel

Carbon steel

It is very commonly used steel in India and globally characterized by its relatively carbon content present in steel. The Cabon content vary between .12 % to 1.5%. Carbon steel is known for its strength and affordability, making it ideal for structural components, machinery, and tools.

Based on carbon contain the carbon steel can be classified on three types

1. Low-carbon steel: The carbon content in low carbon steel can have carbon content up to 0.25%. cold-rolled or annealed steelmaking process used to make this kind of steel. Low-carbon steel have high ductility alone with high weldability, and toughness. This carbon steel used in mainly to make automobile body parts and structural shapes.
2. Medium-carbon steel: The carbon content present in steel vary 0.26% to 0.6%. Due to high carbon content make it compatible to use in tempered and quenched environments. The steel have medium strength and they are ductile and tough.
3. High-carbon steel: High carbon steel is a type of steel that contains high percentages of carbon ranging from 0.60% to 1.5%. The high carbon content resulted into harder and stronger type of steel as compare to other kinds of steel. it is commonly used in applications where durability and resistance to wear such as cutting tools, knives, springs and machine components are important considerations. The high carbon present also cause more fragile and less malleable than low-mid-carbon steels hence it cracks under high stress unless it has been appropriately heat-treated.

The carbon steel price depended on various common factors like input material cost, demand supply scenarios. Change and misbalance in these parameters can caused fluctuation in steel price in India and globally.

Alloy Steel

To brings out desired properties like weldability, strength, hardness, ductility, toughness, corrosion-resistance and more the various alloying components added to the base of steel metal, this type of steel called alloy steel. The amounts of alloying elements may vary between 1 and 50%.

Based on amounts of alloying elements the alloy steel can divided into two categories.

1. Low alloy steel: Low-alloy steels are used in a variety of industrial sectors due to their strength, machinability, and affordability.
2. High-alloy steel: High-alloy steels are used in structural components, automotive applications, chemical processing, and power generating.

Apart from the common factors such as input material cost, demand supply scenarios, the alloy steel price is significantly depended on prices of alloying element. The alloying elements contribution might be less in percentage but it significantly impacts alloy steel price in India and globally.

Alloying Elements & their Impact

Different alloying elements have different impact on steel’s properties as mentioned below.

Manganese: Increases strength, ductility and hardness, and prevents brittleness

Silicon: raised strength, magnetism and hardenability

Chromium: Improves hardenability and makes steel resistant to rust and corrosion

Nickel: raised hardenability and corrosion resistance

Copper: Improves corrosion resistance and adds hardening properties

Phosphorous: raised strength and hardness

Sulphur: raised machineability

Vanadium: raised strength, shock resistance, and adds fine grain structure

Aluminium: raised lightness of steel

Titanium: Reduces martensitic hardness

Tungsten: raise strength and hardness especially in high temperatures

Stainless Steel:

Stainless steel is a versatile and widely used material known for its corrosion resistance, durability, and aesthetic appeal. It is an alloy of chromium, steel and other elements. Stainless steel usually has chromium above 10.5% along with other elements. The composition of stainless steel also makes streel recycling convenient, making it an eco-friendly steel metal type.

The stainless-steel prices depended on chromium and any changes in the chromium prices might affect the stainless-steel price in India and globally.

Based on chromium percentage in steel there are four main types of stainless steel.

Austenitic stainless steel: The key characteristic of austenitic stainless steel is its high chromium and nickel content, typically around 18% chromium and 6-10% nickel. The high chromium and nickel contain provide corrosion-resistant properties, making it highly resistant to oxidation, rust, and staining in various environments austenitic stainless steel is commonly used in applications where corrosion resistance is essential, such as in the chemical, food processing, pharmaceutical, and marine industries.

Ferritic stainless steel: The main characteristic of ferritic stainless steel is its almost zero carbon content and highest chromium with an almost no nickel. This kind of steel contain approx. 10-30 % of chromium. This makes it well-suited for applications where exposure to saltwater or corrosive chemicals is common, such as in automotive exhaust systems, kitchen equipment, and architectural applications.

Martensitic stainless steel: Martensitic stainless steel is a type of stainless-steel alloy known by its high strength, hardness, and wear resistance. The key characteristic of martensitic stainless steel is its high carbon content (usually 0.1% to 1.2%) along with varying levels of chromium (typically between 12% and 18%). Martensitic stainless steel offers excellent strength and hardness, making it suitable for applications requiring resistance to abrasion, wear, and impact. It extensively uses in industries such as cutlery, surgical instruments, industrial blades, and mechanical components which required to material to sustain to high stress and wear.

Duplex stainless steel: This kind of stainless-steel content chromium between 19% to 22%, same some good level of nickel around 4.5% to 6 % along with 3 to 5% molybdenum. Due to its composition this steel has enhanced resistance to corrosion particularly in harsh environments containing chlorides, acids, and caustic solutions.  Which make ideal to use in to applications in sectors like oil and gas, shipping and chemical.

Tool steel

Tool steel can be seen as an ever changing, versatile specialized kind of steel that is designed to make tools, dies and machine parts subjected to high-stress levels, wearing out and striking forces. It is fabricated in manner that it can withstand extreme conditions met during cutting, shaping, forming and machining operations thus making it indispensable in various industrial applications.

The constituents of tool steel usually encompass the combination of alloying elements such as carbon, chromium, vanadium, tungsten among others. These are selected to improve some specific features of the steel such as hardness, resistance to wear and tear or wearability, toughness and heat resistance.

Tool steel price in India totally depended on the domestic demand and supply from manufacturing. Tool steels are categorized into different groups based on their intended use and properties. A few common ones may include:

Carbon tool steel: This type contains mainly carbon hence its high-level hardness and ability to resist abrasion. Much of this product has been used for manufacturing cutting tools like drills or even punches.

High-speed steel (HSS): HSS contains alloying elements like tungsten molybdenum chromium which facilitates great thermal stability while maintaining hardness at elevated temperatures. Drills taps milling cutters etc are most commonly made by HSS.

Cold work alloy steel: Cold work tool steels are made to withstand mechanical stress at low temperatures and are used for dies, punches and cutting-tools operating at or near room temperature.

Hot work tool steels: This type of tool steels is designed to maintain strength and hardness at elevated temperatures particularly for forging dies, extrusion tools and Molds for casting dies.

Shock resisting tool steels: Nickel and molybdenum are added to this steel to increase toughness and resistance to impact loading. It is frequently used in chisels, hammers, high impact tools.