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高速钢工具的耐磨性等性能主要决定于它的硬度和韧性。主要研究了淬火温度和冷速对高速钢韧性的影响。分别在实验室和工业热处理炉中模拟了几种工艺规范，并用静弯曲试验来评估韧性。在同样回火条件下，淬火温度越高，获得的硬度也越高。研究结果显示了低于1200℃淬火的高速钢硬度与韧性之间关系。淬火温度高于1200℃时，韧性显著降低而硬度无明显升高。同时论述了热处理后硬度较低的M2高速钢的力学性能，而某些冷作工具的应用中需要较低热处理硬度。在这种情况下，从较低温度淬火并回火到最高硬度的效果最佳。最后，关于真空炉氮气淬火冷却工艺的研究结果表明，低的淬火压力可以减慢冷速和降低材料韧性，但淬火压力为（6～9）×105 Pa时导致的差别很小。“,”Hardness and toughness are the main properties determining wear resistance and performance of high speed steel tools .The objective of the present paper was to study the effect of hardening conditions on the toughness of high speed steels , mainly concerning the hardening temperature and cooling rate during quenching .Several conditions were simulated in laboratory and industrial heat treatment furnaces and toughness was evaluated through the static bend test .Under the same tempering condition , the higher the hardening temperature , the higher the attained hardness .The results also point out a compromise situation between hardness and toughness , until 1200℃hardening temperature is reached; for temperatures over this value , the loss in toughness become more accentuated , without a considerable increase in hardness . The present paper also describes the mechanical properties of M2 high speed steel heat treated to lower hardness , necessary in some cold work tooling applications . In this case , hardening at lower temperatures and tempering close to the peak hardness has shown the best results . And lastly , regarding cooling conditions during nitrogen hardening in a vacuum furnace , the results point out that low quenching pressures might reduce the cooling rate and decreases material toughness , but the differences are very small for pressures between 6 and 9 ×105 Pa.