MH51 organization subtle, neat, well distributed. And homogeneous. So in terms of wear resistance and a more balanced reform. Especially since only on the carbon content increases or decreases, so does not damage the high-temperature characteristics, continuous and substantial change in the nature of steel. When needed reform of low carbon steel suitable for hardness, wear resistance are required in the circumstances for use of high carbon steel bell. Full of hot, cold plasticity, was cut and ground is also good. MH51 special steel production process using a special solution, with high toughness, high wear resistance, good machinability, heat deformation small. For reamers, taps and other cutting tools for cold, hot forging punch, die-casting mold.
Use
Cutting Tools: Irons, reamer, tap, end mills, broaches, metal saws pressure build tools: must have high toughness and high wear resistance of various molds for cold / hot forging punch, gadolinium, etc. die casting rolls: Multi-roller cold gadolinium machine, slitting machine disc
Edit this section the physical properties
Chemical composition
C: 0.85 Mo: 5.0 Mn: 0.3 Cr: 4.0 Si: 0.3 W: 6.3 [3] V: 1.8 [4]
Heat treatment process
MH51 high-speed steel heat treatment process is more complicated, after annealing, quenching, tempering and a series of processes. The purpose of annealing is to eliminate stress, lower hardness, the microstructure uniformity, ease of quenching. Annealing temperature is generally 860 ~ 880 ℃. Quenching due to its poor thermal conductivity is generally conducted in two stages. First in the 800 ~ 850 ℃ preheating (to avoid large thermal stress), and then quickly heated to quenching temperature of 1190 ~ 1290 ℃ (the actual use of different grades of temperature difference), after the oil-cooling or air-cooled or inflatable body cooling. Salt furnace heating plant are used, the vacuum furnace is used quite widely. After quenching part due to the internal organization also retained (30%) of residual austenite into martensite does not affect the performance of high speed steel. To make residual austenite, to further improve the hardness and wear resistance, generally 2 to 3 times a tempering, tempering temperature of 560 ℃, each holding 1 hour.
(1) manufacturing method: usually electric furnace production, has recently been produced by powder metallurgy high speed steel, so that was a very fine carbide particles uniformly distributed in the matrix, increase the service life.
(2) Usage: used in the manufacture of cutting tools. Such as turning, drilling, hob, machine saw blade and demanding mold.
