Highspeed steel (HSS) is a tool steel with high hardness, high wear resistance and high heat resistance. It is also known as wind steel or front steel, which means that it can harden even if it cools in the air when quenching and is very sharp. It is also called white steel.
Highspeed steel is an alloy steel with complex composition, which contains carbide forming elements such as tungsten, molybdenum, chromium, vanadium and cobalt. The total amount of alloy elements is about 10-25%. It can still maintain a high hardness when high-speed cutting produces high heat (about 500°C), and the HRC can be above 60. This is the most important feature of highspeed steel - redness and hardness. After quenching and tempering at low temperature, although the hardness of carbon tool steel is very high at room temperature, when the temperature is higher than 200°C, the hardness drops sharply. At 500°C, the hardness has dropped to a level similar to that of annealing, completely losing the ability to cut metals, which limits the use of carbon tool steel in making cutting tools. Due to its good redness and hardness, highspeed steel makes up for the fatal shortcomings of carbon tool steel.
High-speed steel is mainly used to make complex thin blades and impact
resistant metal cutting tools. It can also make high-temperature bearings and cold extrusion molds, such as turning knives, drill bits, hobs, machine saw blades and demanding molds.
Tungsten steel
Tungsten steel (hard carbide) has a series of excellent properties such as high hardness, wear resistance, good strength and toughness, heat resistance and corrosion resistance, especially its high hardness and wear resistance. It remains basically unchanged even at a temperature of 500°C, and it still has a high hardness at 1000°C.
Tungsten steel, which is mainly composed of tungsten carbide and cobalt, accounts for 99% of all components and 1% is other metals. Therefore, it is called tungsten steel, also known as cemented carbide, is considered to be the teeth of modern industry.
Tungsten steel is a sintered composite containing at least one metal carbide. Tungsten carbide, cobalt carbide, niobium carbide, titanium carbide and tantalum carbide are common components of tungsten steel. The grain size of carbide components (or phases) is usually between 0.2-10 microns, and carbide grains are combined with metal binders. Bonded metals are generally iron metals, and cobalt and nickel are commonly used. Therefore, there are tungsten-cobalt alloy, tungsten-nickel alloy and tungsten-titanium-cobalt alloy.
Tungsten steel sintering is to press the powder into a billet, then heat it into the sintering furnace to a certain temperature (sintering temperature), keep it for a certain period of time (insulation time), and then cool it to obtain the required properties of tungsten steel materials.
