萘状断口仔晶形成原因及对钻头断裂的影响探讨

Reasons for Incomplete Development Naphthalene Fracture Large Grain and Its Influence on Drill Fracture

生产中发现部分钻头存在萘状断口仔晶,这种晶粒没有完全发育成萘状断口大晶粒形态,本质依然是高速钢的二次再结晶。通过长期的跟踪发现,仔晶对高速钢钻头的韧性造成不利影响,导致产品出现断裂、掰刃现象。通过原材料充分退火,轧制工序适当降低高频频率,热处理工序适当采用较高的预热温度均可以消除这种现象,保证产品质量。

Part of the drill appeared incomplete development naphthalene fracture during the production , the grain was not fully developed into naphthalene fracture large grain , the nature was still secondary recrystallization of HSS .After long-term follow-up found that incomplete development caused adverse effect to the toughness of HSS drill , and lead to prod-ucts appear rupture , break off the blade .The phenomenon can eliminate effectively to ensure the quality of products through raw materials fully annealed , rolling process decreased the frequency of high frequency suitably , heat treatment process suitably used higher preheating temperature .