大颗粒碳化物对W4Mo3Cr4VSi钻头性能的影响

Study of Large Granular Carbides on W4Mo3Cr4VSi Drill Property

生产中发现部分W4Mo3Cr4VSi高速钢钻头出现大颗粒碳化物,导致产品的淬火温度大幅度下降。大颗粒碳化物导致材料中碳化物的弥散度和溶解活性大幅度降低。高速钢的耐火程度亦强烈下降,比正常碳化物材料的耐火温度降低20℃以上。耐火温度的剧烈下降导致钻头的硬度和红硬性的明显降低。大颗粒碳化物以及因其造成的晶粒粗大对钻头的韧性构成危害,是导致钻头断裂和掉块的重要原因。

Part of the W4Mo3Cr4VSi HSS drill appeared large particulate carbide during the production, which result to the quenching temperature of the product was greatly decreased. Large particulate carbide bring about the degree of dis- persion and dissolution activity of carbide in material greatly decreased, refractory degree of HSS strongly decreased, and lower than the normal carbide＇ s above 20℃. A sharp drop in refractory temperature resulted in bit hardness and red hard- ness decreases. Large granular carbide and which caused coarse grain hazard to the toughness of drill, and which were the main reasons causing the drill bit break and block falling.