高速钢分级淬火规范对其组织和性能的影响

The Influence of Speed Steel Hot Quenching Standard inStructure and Properties of Metal

高速钢分级淬火规范对其组织和性能的影响是工具生产中面临的实际问题.本文就此进行了系统的研究.结果表明,随着分级温度的提高,钢的电阻率下降,残余奥氏体量减少,晶界变宽,这说明晶界有碳化物析出.这种析出使钢的硬度、红硬性、抗弯强度、冲击韧性下降,其中冲击韧性的下降最严重.试样尺寸越大,这种影响越显著.在带有冲击的切削试验中发现,分级温度过高使刀具切削性能降低.如W18Cr4V钢车刀在分级温度由600℃提高到675℃时,切削性能下降15%～20%.综上结果,普通高速钢的分级温度以600℃左右或更低些为宜.

The influence of speed steel hot quenching standard in structure and properties of metal is still a real problem in the producing process of tools.All results make clear that in pace with hot quenching temperature going up,the steel resistivity is coming down and the remnants of γ-Fe & copy;are reduced,also the interfaces of grains are widened.These phenomena point out that carbide separated out at the interfaces of grains.This will cause drop in the hardness,hot hardness,bend strength and stamping toughness,especially,stamping toughness.The influence can be noted more easily if the sample size is larger.In the testing of stamping cut,we can see that hot (quenching) temperature that is excessively high will certainly result in drop of cutting (ability) of tools.E.g.W18Cr4V steel lathe tool with the hot (quenching) temperature is ascending from 600 ℃ to 675 ℃,the cutting (ability) is dropping to 15%～20%.To sum up,(ordinary) speed steel hot quenching temperature should be about 600 ℃ or less.