The following is an example of the use of ultra-fine grained carbide YS2, YM051, YM052 and other tool grades in the production of heat-resistant alloy steel.
(1) YS2 cemented carbide
YS2 cemented carbide is an ultra-fine grained cemented carbide produced by Zhuzhou Cemented Carbide Factory. Its performance is equivalent to K30 in ISO standard. Its WC grain size is less than 0.5μ, m, hardness is 91.5HRA, anti- The bending strength is 2200 MPa, and the high temperature hardness at 800 ° C is 930 HV, which is 200 to 300 HV higher than that of the general YG type cemented carbide.
When processing the outer circle of K3 nickel-base casting alloy, under the same cutting amount v=5~6m/min, f=0.5mm/r, ap=0.1mm, the wear of YG8 is about 0.5mm, YS2 is 0.25. Mm; when the flank wear amount is 0.3mm, the tool durability of the YS2 is 15min, while the tool durability of the YG8 or YG8W is less than 5min.
When using YS2 turning tool to process heat-resistant stainless steel Cr17Ni2, when the cutting amount is nf30+0.03mm with n=700r/min, f=0.04min/r, ap=0.5～0.6mm, the precision and surface roughness are guaranteed. Under the condition, the number of workpieces that the tool sharpens once is: 4 to 5 pieces for YT15, 29 to 50 pieces for YT05, and 90 to 140 pieces for YS2. It can be seen that the wear resistance or tool durability of the ultrafine grained cemented carbide YS2 is higher than that of ordinary cemented carbide.
(2) YM series carbide
YM051, YM052 and YM053 are ultra-fine grained hard alloys produced by Shanghai Cemented Carbide Factory. The average grain size of WC is 0.4-0.5μm, more than 95% below 1μm, hardness is greater than 92.5HRA, anti- The bending strength is above 1600 MPa. The versatility of YM051 and YM052 is very strong. It can process steel and cast iron. It is especially effective for processing difficult-to-machine materials such as iron-based, nickel-based superalloy, titanium alloy and heat-resistant stainless steel. YM053 It is mainly used to process all kinds of cast iron.
When turning the end face of GH132 iron-based heat-resistant alloy steel (f62～f400mm), under the same cutting amount n1=45r/min, ap1=1.0mm, f=0.15mm/r, the wear amount of the tool after one knife is taken Yes: YM051 is 0.1mm, YS2 is 0.21mm, YG8 is 0.35mm; when n2=60r/min, ap and f values ​​are unchanged, they are 0.1mm, 0.25mm and 0.27mm respectively. When turning the outer circle, use the same cutting amount n=20r/min, ap=0.8, f=0.07mm/r, and under the condition of cutting fluid, the original high-speed steel turning tool can only be used once. One piece is processed, and the taper is not guaranteed; the YG8 turning tool is easy to produce a chipping knife, and each time the sharpening can only process one piece; and the YS2 or YM052 turning tool can process 2 to 3 pieces after each sharpening, and It can better ensure the taper and surface roughness of the workpiece.
When roughing alloy semi-steel rolls (hardness 60-70HS, size f800×1800mm), the cutting amount is v=17m/min, ap=16mm(YT5) or 20mm(YM052), f=0.625mm/r ( YT5) or 1.75mm/r (YM052), YT5 tool has a significantly lower durability, can only process 200 ~ 300mm, processing efficiency is also low; YM052 can process 500 ~ 600mm, processing efficiency is 2 ~ 3 times YT5.
It can be seen from the above that the ultra-fine grained carbide tool has sharp edges and smooth edges due to its extremely fine grain. At the same time, because of its high strength and hardness, it can keep the blade with a very small circle for a long time. Arc radius and roughness. Therefore, when processing heat-resistant alloy steel, the use of ultra-fine grained carbide tools such as YS2, YM051, YM052, YD05, etc. has better heat resistance and comprehensiveness than the use of YT, YG, YW three types of ordinary cemented carbide knives. The wear resistance not only improves the tool durability, but also improves the cutting efficiency several times, and the surface roughness of the machined workpiece is also significantly reduced. Compared with the cubic boron nitride CBN tool, although it has a slightly lower wear resistance, its price is much lower than that of CBN, so it can be widely applied.
Ultra-fine grained carbide tool for processing heat-resistant alloy steel
Ultra-fine grained cemented carbide is a kind of hard alloy with high hardness, high strength and high wear resistance. Its WC particle size is generally 0.2-1.0μm or less, most of which is below 0.5μ, m, which is ordinary hard. One-minute to one-tenth of the particle size of the WC of the alloy, with the high hardness of the cemented carbide and the strength of the high-speed steel. Its hardness is generally 90 ~ 93HRA, the bending strength is 2000 ~ 3500MPa, higher than the general WC-Co cemented carbide with the same amount of cobalt, and the mutual adsorption-diffusion effect with the processing material is small, especially suitable for heat resistant alloys. Steel, high strength alloy steel and other difficult materials.