Effect of Low-temperature Tempering on Red Hardness of High Speed Steel
A kind of high speed steel-M2 was prepared as experiment material, the value of red hardness improves by 3 HRC, by adding tempering at 360 ℃for 1 h on the basis of original technology. The main reason is low-temperature tempering makes the M3C more fine and dispersed and decreased the amount of large size M3C, all of these provide a condition for carbides nucleation. But when tempered at high temperature, M3C precipitate incompletely, and other kind of carbides will precipitate along with this process, so the effort of dispersion strengthening of the alloys isn't made full used of.