表面层的硬度是材料抵抗局部塑性变形能力。到目前为止，只有硬度的材料参数可以是表面层的直接反映和磨损表面层的抗机械和加工性能。是在高速切削工具及热处理问题的硬度钢，谈论肤浅的看法。表1高速钢刀具刀硬度值的名称推荐推荐硬度值（HRC）的经济过热HSSHSS娥，索爱直柄麻花钻≤?4mm63.5?6664?66不允许有class> ?4mm64?6665?67≤2级大型薄壁齿铣刀密度62?6564?66没有过热工具4?16mm64?6666?67≤2> 16mm65?6766?68≤4齿轮滚刀64?6665?67.5≤2中等齿刀刀

螺旋槽铣刀厚度≤1mm62.5?6564?6550没有过热thickness> 1mm63.5?6665?67≤1铣刀≤?6mm63.5?6665?66.5≤1> ? 6mm64.5?66.565?67≤2三面铣刀刀片厚度≤8mm64 ?6665?67≤1 thickness> 8mm64?66.565?67≤2磨牙机用丝锥M3的?862?6564?66没有过热M> 863?6665 × 67不准过热半圆凸铣刀64 × 6665?67.5≤1切角机63.5 ?6664?67≤1刀63.5 × 6664 × 67不得超过64个推刀?6665?67.5≤1插齿刀64?6665?67≤1刨齿机64?6665?67≤2刀片62 ?6463?65没有过热锥齿轮刀具64?6665?67不许过热常用的高一，高速钢刀具建议的高速钢（HSS）淬火硬度值和普及后，硬度可达63回火?67HRC，高性能高速钢（HSS - E）的，高速钢粉（SPM）的高达66?70HRC。对于某些领域，例如下工具的条件，必须有一个适当的硬度值，表1高速钢切削工具的硬度推荐值的一部分。可以看出，从表1，对一般的工具，如果使用高速钢硬度65?66HRC控制较好，如形式面市，以及高速钢，虽然硬度可达到69?70HRC，但实际上硬度这些刀最良好的范围为66?67HRC。

2工具的硬度和之间的硬度和韧性的关系韧性

集中在刀具上最突出的矛盾，从碳素工具钢，合金工具钢，高速钢，硬质合金刀具材料，以对当前的陶瓷的发展，立方氮化硼等超硬材料，刀具越来越高，硬度高，韧性恶化。在一定意义上，寻求高硬度的工具和许多罕见的高韧性。
在高速钢刀具产品
，只有硬度的具体要求，使用高速钢刀具制造同位外，中心钻有{zd1}硬度（HRCP63）的要求，其余的产品将被63?66HRC，以强硬不作任何要求。

多年的实践证明，硬度太高，但拒绝使刀具寿命。 60年代初，全国会议总工程师工具行业已决定，高速钢刀具硬度66.5HRC不得超过工厂。因为当时的超硬高速钢，粉末高速钢并未作为促进行业发展的工具规定的适用具有指导意义。上世纪70年代，以“日本的学者一般工具来控制硬度65?66HRC的观点”问题。日历从国家银行评估工具的结果，谁是{yl}的产品，优质的产品，年高速钢刀具，其硬度是65HRC以上足以表明，硬度低，不能高的生活。国家规定的{zd1}目标硬度，我认为，只有{zd1}的合格产品，如果连合格的产品无法达到标准，在市场竞争中，没有立足之地。

这里应当特别指出的是，同规格的工具，往往是不同的热处理工艺不同的材料，尽管同一硬度，但不相同的刀具寿命，甚至有一个较大的差距，就是与具有相同的材料规格的工具炉号，也会出现这种情况。只有表面硬度，显微事物的性质，硬度光学测量不看金相不可取的。高硬度不高寿命，刀具寿命的水平，但与硬质合金原料偏折也，粒度硬化，解散的碳化物和锻炼程度，经济过热的程度，以及许多其他因素。热处理工艺的技术要求，通过实现硬度值，热处理，一直是专家，关注其中最重要的淬火加热温度，一点疏忽，将有质量问题。

3结论

的高速切削工具钢刀具寿命的影响硬度的主要指标，硬度高，耐磨性，但韧性差。高硬度边折叠使用易{yj}工具失败，导致：硬度适中，韧性好，使用中难免要磨损，但他们可以研磨工具来恢复原来的功能。当切削材料硬度高，切削工具，在天花板上，相反，得到在下限硬度。硬度63?64HRC的工具，虽然国家标准，但在实际使用，寿命是不会太大。

总之，如何设置高速切削工具的定位，如何匹配的硬度和韧性钢的价值，和工人可能是工具，热的研究工作者永恒的主题待遇。

High-speed steel cutting tool hardness and heat treatment

Hardness of surface layer are material to resist the ability of local plastic deformation. So far, only the hardness of the material parameters can be a direct reflection of the surface layer and the surface of wear-resistant layer of mechanical and process properties. Is on the high-speed steel cutting tools and heat treatment the hardness of the problem, talk about a superficial view. Table 1 high-speed steel cutter knives hardness value name Recommend Recommend hardness value (HRC) level of overheating HSSHSS-E, SPM straight shank twist drill ≤ ?4mm63.5 ~ 6664 ~ 66 not allowed to have class> ?4mm64 ~ 6665 ~ 67 ≤ 2 large thin-tooth milling cutter density 62 ~ 6564 ~ 66 not overheating Tool 4 ~ 16mm64 ~ 6666 ~ 67 ≤ 2> 16mm65 ~ 6766 ~ 68 ≤ 4 gear hob 64 ~ 6665 ~ 67.5 ≤ 2 Medium tooth blade cutter< br="">
screw slot cutter thickness ≤ 1mm62.5 ~ 6564 ~ 65.5 no overheating thickness> 1mm63.5 ~ 6665 ~ 67 ≤ 1 Endmill ≤ ?6mm63.5 ~ 6665 ~ 66.5 ≤ 1> ? 6mm64.5 ~ 66.565 ~ 67 ≤ 2 Three face milling cutter blade thickness ≤ 8mm64 ~ 6665 ~ 67 ≤ 1 thickness> 8mm64 ~ 66.565 ~ 67 ≤ 2 molar machine tap M3 ~ 862 ~ 6564 ~ 66 not overheating M> 863 ~ 6665 ~ 67 are not allowed overheating semicircle convex milling cutter 64 ~ 6665 ~ 67.5 ≤ 1 angle cutter 63.5 ~ 6664 ~ 67 ≤ 1 broach 63.5 ~ 6664 ~ 67 not allowed to push the knife over 64 ~ 6665 ~ 67.5 ≤ 1 gear shaper cutters 64 ~ 6665 ~ 67 ≤ 1 gear-shaping cutter 64 ~ 6665 ~ 67 ≤ 2 cutting blades 62 ~ 6463 ~ 65 not overheating bevel gear cutter 64 ~ 6665 ~ 67 not allowed to overheat one commonly used high-speed steel cutting tools recommend the value of universal hardness of high-speed steel (HSS) quenching and tempering After the hardness up to 63 ~ 67HRC, high-performance high-speed steel (HSS-E), high-speed steel powder (SPM) of up to 66 ~ 70HRC. For a certain cutting tool under the conditions of example, must have an appropriate hardness values, Table 1 high-speed steel cutting tools are part of the recommended values of hardness. As can be seen from Table 1, on the general tool, if the use of HSS hardness 65 ~ 66HRC control is better, like the M42 and the HSS-E, although the hardness can reach 69 ~ 70HRC, but in fact the hardness of most of these knives good range of 66 ~ 67HRC.

2 tool hardness and toughness of the relationship between the hardness and toughness

are concentrated in the cutter on a pair of the most prominent contradictions tool material from carbon tool steel, alloy tool steel, high-speed steel, Cemented to the current development of ceramics, cubic boron nitride and other superhard materials, cutting tool is getting higher and higher hardness, toughness is getting worse. In a sense, seeking tool high hardness and high toughness of many rare.

in the high-speed steel cutting tool products, only the hardness of a specific requirement, using HSS cutting tool manufacture, with the exception of the bit, the center drill has the minimum hardness (HRCP63) requirements, the remaining products will be for 63 ~ 66HRC, for toughness does not make any requests.

decades of practice has proved that the hardness is too high but declined to make the life of cutting tools. The early 60s, the National Conference chief engineer tool industry has decided that high-speed steel cutting tool hardness 66.5HRC shall not exceed the factory. Because at that time the super-hard high-speed steel and powder high-speed steel has not been the application of the provisions as tool for promoting the development of the industry has guiding significance. To the 70’s, the Japanese scholars of “the general tool to control the hardness 65 ~ 66HRC” point of view. Calendar year from the National Bank assessment tool results, who were first-class goods, excellent products, high-speed steel cutting tools, and its hardness above 65HRC are suffices to show that a low hardness can not be the high life. National provides the hardness of the minimum targets, I believe that only the lowest qualified product, if even the qualified products are unable to reach the standards, in market competition there is no foothold.

here should be particularly noted that, with the specifications of tools, often of different materials of different heat treatment process, despite the hardness of the same, but not the same tool life, and even has a larger gap, that is, with the furnace No. with the same material specifications tool, will also appear the situation. Only the surface hardness, microstructure is the nature of things, optical measurement of hardness does not look metallographic undesirable. High hardness is not a high life expectancy, the level of tool life, but also with the raw materials deflectometry carbide, grain size hardening, the degree of carbide dissolution and tempering, the level of overheating, and many other factors. Heat treatment process through which technological requirements to achieve the hardness value, heat treatment has always been a concern of the experts, of which the most important quenching heating temperature, a bit negligent, there will be quality issues.

3 Conclusion

the hardness of high-speed steel cutting tools affect tool life are the main indicators, high hardness, wear resistance, but poor toughness. High hardness in use edge collapse-prone, resulting in permanent tool failure: moderate hardness, good toughness, in-use would inevitably have to wear, but they can make grinding tool to restore the original function. When cutting the material hardness is high, the hardness of cutting tools from the ceiling, on the contrary get in the lower limit. Hardness 63 ~ 64HRC tool, although national standards, but in actual use, the life expectancy are unlikely to be significant.

To sum up, how to set the value of high-speed steel cutting tool positioning, how to match the hardness and toughness, and workers may be the tool, heat treatment of the eternal subject of research workers. (07-12-18)