How to choose the right grade of insert for high-speed turning operations?
■ What is High-Speed Turning?High-speed turning (HST) is a material cutting process involving higher than normal cutting speeds and feed rates, aiming to increase productivity, reduce processing time, and improve the surface quality of the workpiece. However, this process generates high heat, rapid wear, and increased cutting forces, which pose challenges specifically for cutting tools like turning inserts.
■ The Role of Insert Grades in High-Speed Turning
The grade of an insert determines its primary properties such as hardness, wear resistance, toughness, and heat resistance, which are crucial at high speeds. For instance:
- Substrate Material Strength: Needs to be highly durable to withstand cutting forces but not so brittle that it easily breaks.
- Coating: Such as TiAlN, Al2O3, or CVD coating, which helps reduce friction, disperse heat, and minimize wear.
- Microstructure: Should be uniform to prevent weak points during cutting.
Choosing an inappropriate grade for high speeds can result in insert failure or accelerated wear, leading to higher overall costs in the long run.
■ Characteristics of Suitable Insert Grades for High-Speed Turning
Grades ideal for high-speed turning typically feature:
- CVD (Chemical Vapor Deposition) Coatings: Provide excellent hardness and heat resistance, suitable for continuous operations.
- Multi-layer Coating: Such as TiCN/Al2O3/TiN to help reduce the temperature at the cutting edge.
- Tough Substrate Materials: Such as carbide grades enriched with Co or Ni binders to enhance impact resistance.
■ Choosing Grades Based on Material Being Cut
Selecting insert grades should correspond to the workpiece material, such as:
- Carbon Steel: Use P grade with CVD coated Al2O3.
- Stainless Steel: Choose M grade that offers high tensile strength and good toughness.
- Cast Iron: Suitable for K grade that is hard and wear-resistant.
- Aluminum: Use N grade with no coating or a special lubricious coating to prevent material build-up.
■ Why Does Choosing the Right Grade Reduce Costs?
While inserts designed for high-speed operations are more expensive, they can:
- Extend the life of the insert.
- Reduce the need for insert changes during production.
- Increase production rates (shorter cycle times).
- Decrease waste from surface finish issues.
Therefore, although the cost per piece might be slightly higher, the total system cost is reduced.
CONTACT
Contact FormCompany Information
Jigs and tools
Turning Tools / Rotary Tools / Drilling Tools
Mitsubishi Materials carbide tools provide innovative cutting tools and solutions to customers worldwide.