Hongyuan SKH-51 [] [] SKH-51 steel Hongyuan Hongyuan] [SKH-51 tool steel] [Hongyuan Hitachi SKH-51] [Hongyuan SKH-51 pre-hardened material SKH-51] [Hongyuan Clinker SKH-51] [Hongyuan Hongyuan] Price [SKH-51 heat treatment material SKH-51] [Hongyuan hard materials [Hongyuan] [Hongyuan SKH-51 steel rods] SKH-51 Overview Alias: HSS also known as wind steel or speed steel, which means the time of quenching can be cured even if the cooling in the air, and very sharp. It is a complex composition of the alloy, comprising forming elements tungsten, molybdenum, chromium, vanadium, cobalt and other carbide. The total amount of alloying elements up to about 10 to 25%. It produces fever cases in high-speed cutting (about 500 ℃) still maintain high hardness, HRC can in 60 or more. This is the most important characteristic of high speed steel - red hardness. The carbon tool steel after quenching and tempering, at room temperature, although a high hardness, but when the temperature is higher than 200 ℃, the hardness will be a sharp decline, 500 ℃ hardness in the annealed condition and has been reduced to a similar extent completely lost the ability to cut metal, which limits the production of carbon tool steel cutting tools. The high-speed steel due to red hardness is good, to make up for the shortcomings of the deadly carbon tool steel and can be used to manufacture cutting tools. High-speed steel heat treatment process is more complex, must be annealing, quenching, tempering and a series of processes. The purpose of annealing is to eliminate stress, lower hardness, so that a uniform microstructure, easy quenching. Annealing temperature is generally 860 ~ 880 ℃. Quenching due to its poor thermal conductivity generally divided into two phases. First at 800 ~ 850 ℃ preheating (in order to avoid large thermal stress), then rapidly heated to the quenching temperature 1190 ~ 1290 ℃ (different grades of actual use temperature difference), the oil cooling or air cooling, or cooling the inflatable body. Factories are using salt furnace heating, vacuum furnaces are now quite extensive. Due to the internal organization also keep part (about 30%) did not change after quenching residual austenite into martensite, affecting the performance of high speed steel. To make the residual austenite, to further improve the hardness and wear resistance, generally 2 to 3 times a tempering, tempering temperature 560 ℃, each incubated for 1 hour. (1) Manufacturing method: typically produced by an electric furnace, have been recently produced high-speed steel by powder metallurgy, so that very fine carbide particles uniformly distributed in the matrix, improving the service life. Uses (2) Uses: used in the manufacture of cutting tools. Such as turning, drilling, hob, machine saw and demanding mold. Origin: Japan Brand physical properties: Hitachi Chemical Composition Chemical composition (for reference only): Carbon C0.85 Mn0.30 chrome silicon manganese Si0.30 Cr4.00 skh-51 picture W6.30 tungsten molybdenum vanadium V1.80 Mo5.00 Comparison of the mechanical properties of the standard: AISI M2 Factory state: annealing to HB255 uses: Die, embossing dies, cold roll forming, cutting tools, reamers, drills, taps, red top. Forging :100 ℃ -900 ℃. Annealing: heating to 800 ℃ -850 ℃, stay at this temperature for 2-4 hours in the oven to cool gradually. Quenching: the first pre-heated to 550 ℃ -600 ℃. Ci was heated to 950 ℃, and then heated to: 1.220 ℃ -1250 ℃; 2.200 ℃ -1230 ℃. Hardened in oil, but the oil must be incubated 40 ℃ -60 ℃ (general tools; line complex tool toughness are required.). Tempering: heating to 550 ℃ -570 ℃, the temperature stays then cooled missing in still air, tempering should be completed in the second. Hardness: HRC63 or more.