Experimental investigation into tool wear of cemented carbide cutting inserts when machining wear resistant steel Hardox

    
    Introduction
    
    Wear resistant tool steels such as Hardox 500 and Hardox 1000 are becoming increasingly popular in a variety of machining applications. Several factors such as hardness and strength of the material, as well as the cutting geometry and cutting parameters affect the tool life and machining performance. In particular, the tool material and its wear characteristics should be carefully optimized for the specific cutting application. In this study, an experimental investigation has been conducted to evaluate the tool wear of cemented carbide cutting inserts when machining wear resistant steel Hardox 500 and Hardox 1000.
    
    Theory
    
    Cemented carbide cutting inserts are used in metal cutting applications due to their high hardness, wear and heat resistance. Typical cutting parameters such as speed, feed and depth of cut need to be adjusted or optimized according to the cutting operations so as to minimize tool wear. When machining wear resistant steels, attention should be paid to the selection of cutting insert material, insert geometry and cutting force. These parameters affect the tool wear and the cutting performance.
    
    Experiment Design and Procedure
    
    The current experimental investigation was conducted using two different worn resistant steels, Hardox 500 and Hardox 1000, on a conventional lathe machine with a cutting speed of 1000 rpm, a feed rate of 0.1 mm
    ev and a depth of cut of 0.4 mm. The parameters for the inserts were round-shaped with a diameter of 12 mm, an included angle of 80 degrees and a nose radius of 4 mm. A total of 24 inserts of different sizes and shapes were used for each Hardox 500 and Hardox 1000 steel.
    
    The experiment was divided into three stages: (1) cutting of the Hardox 500 and Hardox 1000 steels; (2) measurement of tool wear; and (3) analysis of cutting forces. During Stage 1, all 24 inserts were used to machine the Hardox 500 and Hardox 1000 steels to obtain an initial machined surface. During Stage 2, the wear characteristics of the cutting edges were measured with a microscope. The wear was also visually inspected under 10x and 20x magnifications. During Stage 3, cutting forces were measured with a force transducer attached to the cutting tool.
    
    Results and Findings
    
    The experiment results showed that cemented carbide cutting inserts significantly influenced tool wear and cutting performance when machining Hardox 500 and Hardox 1000 steels. The results indicated that the round-shaped insert with an included angle of 80 degrees demonstrated the lowest wear rate, followed by the square-shaped insert with an included angle of 90 degrees and the triangle-shaped insert with an included angle of 60 degrees. It can also be seen from the results that the nose radius of 4 mm yielded the lowest wear rate. The cutting forces measured from the experiment showed that the round-shaped inserts with an included angle of 80 degrees demonstrated the lowest cutting forces, followed by the square-shaped insert with an included angle of 90 degrees.
    
    Conclusion
    
    The results of the experiment demonstrated that the round-shaped cemented carbide insert with an included angle of 80 degrees, a nose radius of 4 mm and a cutting speed of 1000 rpm yielded the best tool wear characteristics and cutting performance when machining Hardox 500 and Hardox 1000 steels. The results can provide useful guidelines for the selection of cutting tool material and parameters to achieve better machining performance.

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