Q&A

1. High hardness and wear resistance

Hardness is a fundamental characteristic that cutting blade materials should possess. The mechanical blade needs to cut chips from the workpiece, and its hardness must be greater than the hardness of the workpiece material. The cutting edge hardness of the cutting blade used for metal cutting is generally above 60HRC. Wear resistance is the ability of a material to resist wear. Generally speaking, the higher the hardness of the cutting blade material, the better its wear resistance. The higher the hardness and quantity of hard points (carbides, nitrides, etc.) in an organization, the smaller and more evenly distributed the particles, and the better the wear resistance. Wear resistance is also related to the chemical composition, strength, microstructure, and temperature of the friction zone of the material. The wear resistance of the material can be expressed using the formula WR: WR=KICO.5E-0.8H1.43. In the formula, the higher the daily material hardness (GPa) e, the better the wear resistance.

2. Sufficient strength and toughness

In order for the cutting tool to work under high pressure, as well as the impact and vibration conditions that often occur during the cutting process, without causing blade breakage and breakage, the cutting tool material must have sufficient strength and toughness.

3. High heat resistance (thermal stability)

Heat resistance is the main indicator for measuring the cutting performance of cutting blade materials. It refers to the performance of mechanical blade materials to maintain a certain degree of hardness, wear resistance, strength, and toughness under high temperature conditions. The cutting blade material should also have the ability to resist oxidation at high temperatures, as well as good resistance to adhesion and diffusion, that is, the protective material should have good chemical stability.

4. Good thermal physical properties and heat shock resistance

The better the thermal conductivity of the cutting blade material, the easier it is for cutting heat to dissipate from the cutting zone, which is beneficial for reducing cutting temperature. When cutting intermittently or using cutting fluid, the cutter is often subjected to significant thermal shock (drastic temperature changes), resulting in cracks inside the cutter and leading to fracture. The ability of cutting blade materials to resist thermal shock can only be expressed by the heat resistance impact coefficient, and the definition of R is: R=entering ab (1-u)/Ea

In the formula:

Enter the thermal conductivity coefficient;

Ab - tensile strength;

Mu Yi Ning Bai Song Bi;

E - elastic modulus;

A-coefficient of thermal expansion.

The high thermal conductivity makes it easy for heat to dissipate and reduces the temperature gradient on the surface of the cutting blade; The coefficient of thermal expansion is small, which can reduce thermal deformation; The small elastic modulus can reduce the amplitude of alternating stress caused by thermal deformation; Beneficial for improving the heat resistance and impact resistance of materials. Cutting blade materials with good heat resistance and impact resistance can use cutting fluid during cutting processing.

5. Good process performance

In order to facilitate the manufacturing of cutting blades, it is required that the cutting blade material has good process performance, such as forging performance, heat treatment performance, high-temperature plastic deformation performance, grinding processing performance, etc.

6. Economy

Economy is one of the important indicators of cutting blade materials. Although the cost of a high-quality cutting blade material is high for a single mechanical blade, due to its long service life, the cost allocated to each component may not be very high. Therefore, when selecting cutting blade materials, their economic effects should be comprehensively considered.