● High speed steel

High speed steel refers to high alloy tool steel containing more alloying elements such as tungsten, chromium, molybdenum and vanadium. High speed steel can be divided into ordinary high speed steel and high performance high speed steel according to different uses.

General purpose high speed steel has a certain hardness (63-66HRC), wear resistance, high strength and toughness. When processing ordinary steel, the cutting speed is 50-60m/min, which is not suitable for high-speed cutting and superhard material processing. W18Cr4V and W6Mo5Cr4V2 are the main brands. The latter is superior to the latter in strength and toughness, but has poor thermal stability.

● Hard alloy

Powder metallurgy products are made of hard alloy (WC, TiC, TaC, NbC, etc.) with high hardness and high melting point. , Co, Mo, Ni and other elements as binder. Its room temperature hardness can reach 78-82HRC, can be used at high temperature 800-1000℃, its cutting speed is 4 to 10 times that of high-speed steel. However, their impact toughness and bending strength are much lower than those of high speed steel, so they are rarely used as integral tools. In practice, the carbide tool block is usually fixed to the tool body by welding or mechanical clamping.

Large CNC lathe equipment commonly used carbide has the following three kinds:

1. Cobalt tungsten carbide (code YG) is composed of tungsten carbide and cobalt.

This hard alloy has good toughness, but poor hardness and wear resistance, and is suitable for processing brittle materials (such as cast iron, etc.). The more Co in cobalt tungsten carbide, the better the toughness. Commonly used brands are: YG8, YG6, YG3, the cutting tools in turn for rough machining, semi-finishing and finishing.

2. Tungsten-titanium cobalt carbide (YT) is composed of tungsten carbide, titanium carbide and cobalt.

This hard alloy has good heat resistance and wear resistance, but poor impact toughness, and is suitable for cutting plastic materials such as strip steel. Commonly used brands are YT5, YTl5, YT30, etc., where the number represents the content of titanium carbide. The higher the content of titanium carbide, the better the wear resistance and the lower the toughness. Tungsten, titanium, cobalt three brands of tools are suitable for rough machining, semi-finishing and finishing respectively.

3. Tungsten-titanium tantalum (niobium) hard alloy (code YW) is composed of tungsten-titanium cobalt hard alloy and a small amount of tantalum carbide (TaC) or niobium carbide (NbC).