Mon Jul 04 14:05:47 CST 2022
The improvement and development of tool material is one of the important topics in the development of metal processing today, because good tool material can effectively and quickly complete the cutting work, and maintain a good tool life. The commonly used turning tool materials are as follows:
High carbon steel turning tool is a carbon steel with carbon content between 0.8%~1.5%, after quenching and hardening, because of the friction in cutting is easy to temper and soften, is replaced by other tools such as high-speed steel. Generally only suitable for the cutting of soft metal materials, commonly used SK1, SK2、SK7 and so on.
High speed steel is a kind of steel base alloy white turning tool. It is made of carbon steel with W, Cr, V, Co and other alloying elements. It contains 0.7~0.85% carbon. For example, 18-4-4 HSS contains 18% tungsten, 4% chromium and 4% vanadium. The friction heat generated in the cutting of high speed steel turning tool can be up to 6000C, suitable for turning speed below 1000rpm and thread, generally used high speed steel turning tool such as SKH2, SKH4A, SKH5, SKH6, SKH9 and so on.
This is cobalt, chromium and tungsten alloy, because the cutting is difficult, to casting forming manufacturing, so it is also called super hard casting alloy, the most representative is Stellite, its tool toughness and wear resistance is excellent, at 8200C temperature its hardness is still not affected, heat resistance is far beyond high speed steel, suitable for high speed and deep cutting work.
Carbide tool for powder metallurgy products, tungsten carbide tool main composition is 50%~90% tungsten, and add titanium, molybdenum, tantalum to cobalt powder as a binder, and then through heating sintering. Carbide cutting tools of hardness is higher than any other material, has the most hard three times of high carbon steel, suitable for cutting hard metal or stone material, because its material brittle hard, so can only be made into sheet, welded again in its toughness on the handle, so the blade passivation or split, can change another new blade, blade or change this enough tool called abandon type lathe tool.
Carbide tool according to the international standard (ISO) its cutting properties of different, divided into P, M, K three categories, and respectively in blue, yellow, red three colors to identify:
P is suitable for cutting steel, there are P01, P10, P20, P30, P40, P50 six categories, P01 for high-speed fine turning tool, small number, high wear resistance, P50 for low speed rough turning tool, large number, high toughness, handle painted blue to identify it.
Class K is suitable for cutting stone, cast iron and other brittle hard materials, there are K01, K10, K20, K30, K40 five categories, K01 for high-speed fine turning tool, K40 for low speed rough turning tool, this kind of handle coated with red to identify.
Class M is between class P and class M, suitable for cutting materials with greater toughness. Steel? The handle of this kind of knife is painted yellow to identify it.
Ceramic turning tool is made of aluminum oxide powder, add a small amount of elements, and then sintered through high temperature, its hardness, heat resistance, cutting speed is higher than tungsten carbide, but because of brittle quality, it is not suitable for discontinuous or heavy turning, only suitable for high-speed finishing.
For advanced finishes, round or edged industrial diamonds may be used for finishing. Can get more smooth surface, mainly used to do copper alloy or light alloy precision turning, turning must use high speed, the lowest need in 60~100m/min, usually in 200~300m/min.
Cubic crystalline boron oxide (CBN) is a material popularized in recent years, hardness and wear resistance second only to diamond, this turning tool is suitable for processing hard, wear resistant iron alloy and nickel base alloy, cobalt base alloy.