What cutting tools should be selected for stainless steel parts machining? Currently, there are two commonly used tool materials: high-speed steel and cemented carbide. Different choices are made based on different cutting characteristics. The following is an analysis of tool selection for stainless steel parts machining.
Tool Selection for Stainless Steel Parts Machining
I. Selection of High-Speed Steel:
1. High-speed steel is mainly used to manufacture complex multi-edge tools such as end mills, drills, taps, and broaches. The tool life of ordinary high-speed steel W18Cr4V is very low and no longer meets the requirements. Using new-type high-speed steel tools to cut stainless steel parts can achieve better results.
2. Under the same turning conditions, when tools made of W18Cr4V and 95W18Cr4V are used to machine 1Cr17Ni2 workpieces, the number of parts processed per tool regrinding is 2–3 pieces and 12 pieces, respectively. The tool life of 95W18Cr4V is improved several times.
3. This is because the carbon content of the steel is increased, thereby increasing the carbide content in the steel. The hardness at room temperature is increased by 2 HRC, and the red hardness is better. At 600°C, the hardness rises from HRC48.5 for W18Cr4V to HRC51–52, and the wear resistance is 2–3 times higher than that of W18Cr4V.
II. Selection of Cemented Carbide:
1. YG-type cemented carbide has good toughness, allowing a larger rake angle, and the cutting edge can be ground sharper, making cutting lighter and reducing the tendency for chips to adhere to the tool. It is therefore more suitable for machining stainless steel. This advantage of YG-type alloys is especially important during vibrating rough turning and intermittent cutting.
2. In addition, YG-type alloys have good thermal conductivity, with a thermal conductivity coefficient nearly twice that of high-speed steel and twice that of YT-type alloys. Therefore, YG-type alloys are widely used in stainless steel cutting, especially in the manufacture of rough turning tools, cut-off tools, core drills, and reamers.
3. For a long time, ordinary grades of cemented carbide such as YG6, YG8, YG8N, YW1, and YW2 have been used as tool materials for cutting stainless steel, but none have achieved ideal results. Using new-grade cemented carbides such as 813, 758, 767, 640, 712, 798, YM051, YM052, YM10, YS2T, and YD15 can achieve better results in stainless steel cutting.
4. The 813 cemented carbide tool performs very well in cutting stainless steel because 813 not only has high hardness (≥HRA91) and strength (σb=1570MPa), but also good high-temperature toughness, oxidation resistance, and anti-adhesion properties, with a dense structure and good wear resistance.
