New Breakthrough in Tool Material Development

Steel turning is one of the major fields of processing. Almost all workshops have this process, which means that steel parts can be applied regardless of material type, workpiece type, process type and batch size. This is mainly used for parts processing in the application range of ISO P25. Its processing conditions are from good to bad, so it is important to improve the processing performance. Since the introduction of coated indexable blade, a blade material has been a conventional solution for this kind of widely used. P25 material can continuously improve processing. This is the general steel turning material, which can also optimize a large number of processes. Now, the performance is significantly improved through the innovation of tool materials, which is more than any similar material improvement in the past.
Harsh environment
The cutting edge of any tool is subjected to thermal compression. In the cutting process, when the workpiece material is close to the cutting edge, the cutting edge is first taken at the main cutting edge. Then, after the main cutting edge, the rake face plays a major role in the iron chip flow. Auxiliary shear plane with large amount of energy transfer. In steel turning, the resultant force is large (1400~3100 N/mm2, which varies with different steel types) and the temperature is high (up to 1000 ℃). It is in the iron chip flow area that the ability of tool materials is tested to determine the main impact of processing operations.  
 
The combination of the chip edge groove type and the tool material with a short distance along the edge line of the chip breaking groove on the indexable insert determines the effect of the shear stress, because the chip load on the entire surface is concentrated, and then takes away most of the heat generated in processing. Friction is a major factor, so the texture of the iron chip contact surface and the blade surface plays an important role in the performance.
 
The wear mechanism of iron chip flow zone in steel processing is mainly chemical melting, and there is a tendency of partial plastic deformation. Diffusion wear is the main feature of high speed cutting. At the same time, there is also abrasive wear, which mainly occurs in the clearance surface of the blade. These wear are continuous and controllable. Steel turning must achieve continuous and controllable wear, such as main plastic deformation, hot cracking and groove wear.
 
Steel turning
Steel turning is a common processing application in the world, which is used in many metalworking workshops. However, due to the use of a variety of materials, from non alloy steel, low alloy steel to high alloy steel, from soft viscous materials to hard abrasive materials, the physical properties and conditions vary greatly. The machinability grades of bars, tubes, forgings, castings, rolled, drawn, untreated, quenched and tempered and pre machined workpieces are obviously different due to their different materials. These fall within the scope of application of ISO P25 for steel turning. Considering the different wear mechanisms of different steel parts, it is impossible to use one blade material for all processing applications. Therefore, the production types of the whole field (whether small batch production between small cars or large batch production between large cars) are different, and it is impossible to adopt the same processing technology.
 
However, since 1970, the introduction of coated cemented carbide materials has made revolutionary progress in steel turning. Over the years, six generations of P25 materials have been developed to continuously improve the processing performance and greatly improve the production efficiency. By using general steel turning materials, many applications can be optimized. The seventh generation P25 blade material is upgrading its performance.
 
It is no exaggeration to develop a new generation of P25 blade material for steel cutting, which completely changes the rules of the manufacturing game. This is a major progress in cutting tool material science, which can meet the needs of modern production and overcome many technical difficulties: predictability of tool life, continuity of machining parts quality and higher cutting speed.
 
This new achievement is entirely due to the intensive and rich research and development of coated cemented carbide inserts, not only for material science, but also for application analysis and blade manufacturing technology. When designing new steel turning materials, a variety of factors need to be evaluated and studied, including raw materials, hard particle mixtures, adhesives, particle size, matrix gradient design, and more importantly, coating technology.