Alloy steel

Alloy steel — is a steel that includes various alloying elements that give the steel the required mechanical and physical properties.

These elements also significantly increase corrosion resistance, resistance to brittleness and increase strength.

Alloy steel elements  can be put on the following list:

• nitrogen;
• copper;
• nickel;
• chromium;
• vanadium.

These are classic additives that are widely used in production. Alloy steel is divided into three main classes:

• low-alloy;
• high-alloy;
• medium-alloy.

Alloy steels are classified based on the percentage of alloying elements. Each of these steel types is produced by metallurgy, but in some cases, alloying may only be performed on a specific surface to impart the required strength properties to products and components. Alloy steel acquires its properties at various stages of metal production, as alloying elements are added. Alloy steel may include one or more alloying elements, which increase the structural strength of the alloy. Alloy steel is produced in several main types:

• instrumental;
• structural;
• steel with special chemical and physical properties.

Marking of alloy steels

Alloy steels are marked using letters indicating the alloying element contained in the alloy and numbers indicating the average percentage of that element. The numbers at the beginning of the grade name indicate the carbon content of the material. Two numbers indicate hundredths of a percent; one number indicates tenths. Marking of alloy steels may have additional designations. For example, the following common designations are present:

• P — high-speed;
• Ш – ball bearing;
• A - automatic;
• L - obtained by casting;
• E — electrical engineering.

The nitrogen content is indicated by the letter A in the middle of the grade. Two A's (AA) indicate the composition of ultra-pure steel and appear at the end. High-quality steel ends with the letter Ш. Examples of alloy steel markings:

18ХГТ means:

• 0.18% C;
• 1% Cr;
• 1% Mn;
• 0,1% Ti.

Steel 30KhGSA contains:

• 0.30% C;
• 0.8-1.1% Cr;
• 0.9-1.2% Mn;
• 0.8-1.25% Si.

Purpose of alloy steels

Purpose of alloy steels The range of alloy steels is very diverse, as, with the appropriate alloying additives, this steel is capable of withstanding a wide range of loads, unlike standard steel. Most properties can be adjusted by adding the appropriate alloying elements. The primary purpose of alloy steels is the manufacture of surgical instruments, jewelry equipment, various metal structures, construction reinforcement, industrial machinery, and mechanisms subject to heavy loads. Tool-grade alloy steels are used to manufacture components operating under high pressure, as well as in the manufacture of master gears, complex rollers, forging die sections, etc. Other grades are used for components requiring increased wear resistance, good bending strength, contact load resistance, and the required excellent elasticity.

Types of alloy steel

Alloy steel types are differentiated based on the percentage of alloying elements in the alloy. The following are classified:

• low-alloy and contain up to 2.5% alloying elements;
• medium-alloyed, having from 2.5 to 10% alloying elements;
• High-alloy ones have 10 - 50% of such elements.

Types of alloy steel They vary. They are classified based on the percentage of high-performance components, such as zirconium, vanadium, tantalum, and other chemical elements, such as carbon, as well as structural specifics:

• ledeburite – presence of primary carbides;
• eutectoid – the metal structure is pearlitic;
• hypereutectoid – presence of secondary carbides;
• hypoeutectoid – there is excess ferrite.

Depending on the degree of use and purpose, steels are classified as: structural, tool, and with special properties.

Types of alloy steel These also include stainless steels, which have excellent resistance to chemical and electrochemical corrosion. Special heat-resistant steels offer good resistance to chemical degradation in a gas environment at temperatures above 500°C, but they operate under light or no load. Heat-resistant steels operate under heavy loads for a considerable period while maintaining sufficient heat resistance. Types of alloy structural steel include:

• high quality;
• high quality;
• very high quality.