P20 mold steel is a type of pre-hardened steel that is widely used for making large and complex molds and dies. P20 mold steel has a good balance of strength, toughness and wear resistance. However, machining P20 mold steel can be challenging due to its high hardness and low thermal conductivity.
CNC tungsten steel milling cutters are a suitable choice for processing P20 mold steel. CNC tungsten steel milling cutters are made of tungsten carbide, which is a hard and wear-resistant material that can withstand high temperatures and pressures. Tungsten carbide consists of hard tungsten carbide particles bonded by a soft metal like cobalt.
CNC tungsten steel milling cutters can perform various types of milling operations on P20 mold steel, such as face milling, square shoulder milling, slot milling, etc. The quality and efficiency of CNC tungsten steel milling cutters depend on several process parameters, such as cutting speed, feed rate, depth of cut, etc. These parameters affect the tool wear rate, material removal rate and surface roughness of the machined workpiece.
To optimize the process parameters of CNC tungsten steel milling cutters for processing P20 mold steel, different methods can be used, such as response surface methodology (RSM), multi-objective optimization (MOO), deep cryogenic treatment (DCT), etc. RSM is a statistical technique that uses a design of experiments to model the relationship between the process parameters and the performance measures. MOO is a mathematical technique that aims to find the best compromise solution among multiple conflicting objectives. DCT is a physical technique that involves cooling the cutting tool to very low temperatures for a certain duration to improve its microstructure and properties.
In this article, we will review some of the research studies that have applied these methods to optimize the process parameters of CNC tungsten steel milling cutters for processing P20 mold steel.
RSM and MOO for CNC tungsten steel milling cutters
One of the studies that used RSM and MOO for CNC tungsten steel milling cutters was conducted by Mukkoti et al1. They investigated the effect of DCT soaking duration on the machinability of P20 mold steel using tungsten carbide end mill cutter. They used a Box-Behnken design of RSM to collect data for four process variables: cutting speed, feed rate, depth of cut and DCT soaking duration. They measured three performance measures: tool wear rate, material removal rate and surface roughness. They used NSGA-II, which is a popular MOO technique, to obtain the optimal process parameters for enhancing the productivity of the end milling process. They found that DCT soaking duration had a significant effect on the performance measures and that NSGA-II was able to provide a set of optimal solutions for different preferences.
DCT for CNC tungsten steel milling cutters
Another study that used DCT for CNC tungsten steel milling cutters was conducted by Yong et al2. They studied the effect of DCT on the wear behavior and cutting performance of tungsten carbide end mill cutter in high-speed machining of hardened steel. They compared three types of cutting tools: untreated, shallow cryogenic treated (SCT) and DCT. They measured the tool wear rate, cutting force and surface roughness under different cutting speeds and feed rates. They also performed microstructural analysis and hardness tests on the cutting tools. They found that DCT improved the wear resistance and cutting performance of tungsten carbide end mill cutter by increasing its hardness and reducing its cobalt leaching.
Cutting data recommendations for CNC tungsten steel milling cutters
A general guideline for selecting the cutting data for CNC tungsten steel milling cutters can be found in Uddeholm’s datasheet 3. They provided some typical values for cutting speed, feed rate and depth of cut for different types of milling operations using uncoated HSS or coated cemented carbide tools. They also gave some remarks on the use of coolant, cutter geometry and climb milling. However, they noted that these values are only general guidelines and may have to be adjusted to the actual conditions of a specific machining operation.
Conclusion
CNC tungsten steel milling cutters are a versatile and efficient cutting tool that can machine various hard and tough materials such as P20 mold steel. However, to achieve the best performance and productivity of CNC tungsten steel milling cutters, it is important to optimize the process parameters according to the specific machining operation and workpiece material. Different methods can be used to optimize the process parameters, such as RSM, MOO and DCT. These methods can help to improve the tool wear rate, material removal rate and surface roughness of CNC tungsten steel milling cutters.
1: Mukkoti VV., Mohanty CP., Gandla S., Sarkar P., Rao PS., B D. Optimization of process parameters in CNC milling of P20 steel by cryo-treated tungsten carbide tools using NSGA-II [Internet]. Production & Manufacturing Research An Open Access Journal 2020;8(1):291–312 [cited 2023 May 10]. Available from: https://www.tandfonline.com/doi/full/10.1080/21693277.2020.1790436
2: Yong AY., Venkatesh VC., Rajendran I., Che Haron CH., Sharif S., Noordin MY., et al. Performance evaluation of cryogenically treated tungsten carbide tools in high-speed end-milling [Internet]. Journal Of Materials Processing Technology 2007;185(1-3):62–71 [cited 2023 May 10]. Available from: https://www.sciencedirect.com/science/article/abs/pii/S0924013606004219
3: Uddeholm Global. Cutting data recommendations - Uddeholm Corrax [Internet]. 2018 [cited 2023 May 10]. Available from: https://www.uddeholm.com/files/Cutting_Data_Corrax_eng.pdf
