High Speed Steel Properties
High speed tool steel is always doing metallography and hardness test,instead of tensile strength test.Tungsten & Molybdenum HSS can reach more than 63HRC after proper heat treatment.Cobalt high speed steel can up to 65HRC.
HSS Steel pickling macrostructure shrinkage cavity, skull patch whicn is not visible. General osteoporosis of High-speed steel should be less than 1 level.
Metallographic examination content mainly includes the decarburization layer, microstructure and carbides uneven degree.
1. High speed steel should not have obvious decarburization. The microstructure herringbone eutectic ledeburite may not exist.
2. The carbide in high speed steel is not uniformity had the greatest influence on quality, metallurgy and mechanical department of carbide evenness level very seriously. According to the different USES of steel can be put forward different levels of carbide is not uniformity requirements, normally should be less than 3 level.
3. Tools made of high speed steel, in addition to because of its high hardness, high wear resistance and toughness enough, there is another important factor is a red hardness. (red hardness refers to the cutting tool in high speed cutting, the blade in the red state’s ability to fight softening.)
A method of measuring red hardness is the first steel heating to 580 ~ 650 ℃, heat preservation for 1 hour, and then cooling, this repeated 4 times after measuring its hardness value. High speed steel quenching temperature is close to the melting point of steel, such as tungsten series high speed steel is 1210 ~ 1240 ℃, high molybdenum HSS is 1180 ~ 1210 ℃. Usually required after quenching tempering three times between 540 ~ 560 ℃. Improve the quenching temperature can increase the red hardness of steel. In order to improve the service life of HSS cutting tools, to strengthen the surface processing, such as low temperature cyanide, nitrogen, sulfur and nitrogen altogether permeability, etc.
High speed steel manufacturers and suppliers in China, supplied in round bar,square bar,flat bar,plate,sheet and wire.