Classification and application of common cemented carbide

2020-06-03

Commonly used hard alloys are divided into three categories according to their composition and performance characteristics: tungsten-cobalt, tungsten-titanium-cobalt, and tungsten-titanium-tantalum (niobium). The most widely used in production are tungsten-cobalt and tungsten-titanium-cobalt cemented carbides.
(1) Tungsten-cobalt cemented carbide
The main components are tungsten carbide (WC) and cobalt. The grade is code-named YG ("Hard" and "Cobalt" in Chinese Pinyin prefix), followed by the percentage value of cobalt content. For example, YG6 represents a tungsten-cobalt cemented carbide with a cobalt content of 6%, and a tungsten carbide content of 94%.
(2) Tungsten titanium cobalt carbide
The main components are tungsten carbide (WC), titanium carbide (TiC) and cobalt. The grades are code-named YT ("Hard", "Titanium" in Chinese Pinyin prefix), followed by the percentage value of titanium carbide content. For example, YT15 represents tungsten titanium cobalt cemented carbide with 15% titanium carbide content.
(3) Tungsten titanium tantalum (niobium) carbide
This kind of cemented carbide is also called general cemented carbide or universal cemented carbide. The main components are tungsten carbide (WC), titanium carbide (TiC), tantalum carbide (TaC) or niobium carbide (NbC) and cobalt. The brand name is represented by the code YW ("Hard" and "Wan" prefix of Chinese Pinyin) followed by the ordinal number.
Application of cemented carbide
(1) Tool material
Carbide is the largest number of tool materials, which can be used for turning tools, milling tools, planing tools, drills, etc. Among them, tungsten-cobalt cemented carbide is suitable for short cutting of ferrous and non-ferrous metals and non-metallic materials, such as cast iron, cast brass, bakelite, etc.; tungsten-titanium-cobalt cemented carbide is suitable for the growth of ferrous metals such as steel Chip processing. Among similar alloys, those with more cobalt content are suitable for rough machining, and those with less cobalt content are suitable for finishing. General hard alloys have a much longer processing life than stainless steel and other difficult-to-machine materials.
(2) Mold material
Cemented carbide is mainly used as cold work die such as cold die, cold die, cold extrusion die, cold pier die.
Under the wear-resistant working conditions of hard alloy cold heading die under impact or strong impact, the commonality is that the hard alloy has good impact toughness, fracture toughness, fatigue strength, bending strength and good wear resistance. Usually, medium and high cobalt and medium and coarse grain alloy grades are used, such as YG15C.
Generally speaking, the relationship between wear resistance and toughness of cemented carbide is contradictory: the increase in wear resistance will lead to a decrease in toughness, and the increase in toughness will inevitably lead to a decrease in wear resistance. Therefore, when selecting alloy grades, it is necessary to meet specific use requirements according to the processing objects and processing working conditions.
If the selected brand is prone to cracking and damage early in use, a brand with higher toughness should be selected; if the selected brand is prone to early wear and damage during use, a brand with higher hardness and better wear resistance should be used . The following grades: YG6C, YG8C, YG15C, YG18C, YG20C from left to right, the hardness is reduced, the wear resistance is reduced, and the toughness is improved; otherwise, the opposite is true.
(3) Measuring tools and wear-resistant parts
Cemented carbide is used for wear-resistant parts such as inlays and parts of measuring tools that are easy to wear, precision bearings for grinding machines, guide plates and guide rods for centerless grinding machines, and lathe centers.