This type of steel refers to alloy steels suitable for the manufacture of machines and mechanical parts. It is based on high-quality carbon turbulent steel, and one or several alloying elements are properly added to improve the strength, toughness and hardenability of the steel. This type of steel is usually used after heat treatment (such as quenching and tempering treatment, surface hardening treatment). It mainly includes two categories of commonly used alloy structural steel and alloy spring steel, including quenched and tempered alloy steel, surface hardened alloy steel (carburizing steel, nitrided steel, surface high-frequency quenching steel, etc.), cold plastic forming Use alloy steel (steel for cold upset forging, steel for cold extrusion, etc.). According to the basic composition series of chemical composition, it can be divided into Mn series steel, SiMn series steel, Cr series steel, CrMo series steel, CrNiMo series steel, Nj series steel, B series steel, etc.

Alloy structural steel

The carbon content wc of alloy structural steel is lower than that of carbon structural steel, generally in the range of 0.15% to 0.50%. In addition to carbon, it also contains one or several alloying elements, such as silicon, manganese, vanadium, titanium, boron and nickel, chromium, molybdenum, etc.
Alloy structural steel is easy to harden and not easily deformed or cracked, and it is convenient for heat treatment to improve the performance of the steel.
Alloy structural steel is widely used in the manufacture of various transmission parts and fasteners for automobiles, tractors, ships, steam turbines, and heavy machine tools. Low carbon alloy steel is generally carburized, and medium carbon alloy steel is generally quenched and tempered.

alloy tool steel

Alloy tool steel is medium and high carbon steel containing a variety of alloying elements, such as silicon, chromium, tungsten, molybdenum, vanadium, etc. Alloy tool steel is easy to harden, not easy to deform and crack, and is suitable for making cutting tools, molds and measuring tools with large size and complex shape.
For different purposes, the carbon content of alloy tool steel is also different. The carbon content wc of most alloy tool steels is 0.5% to 1.5%. Steel for hot deformation molds has low carbon content, wc is in the range of 0.3% to 0.6%; steel for cutting tools generally contains about 1% carbon wc; steel for cold working molds has higher carbon content, such as graphite mold steel carbon content wc Up to 1.5%, the carbon content wc of high-carbon and high-chromium cold-working mold steel is as high as 2%.

High speed tool steel

High-speed tool steel is a high-carbon high-alloy tool steel. The carbon content wc in the steel is 0.7%-1.4%. The steel contains alloying elements that can form high-hardness carbides, such as tungsten, molybdenum, chromium, and vanadium.
High-speed tool steel has high red hardness. Under high-speed cutting conditions, the hardness does not decrease even when the temperature is as high as 500-600 degrees Celsius, thus ensuring good cutting performance.