拉刀崩齿断裂分析

Failure Analysis on the Broaches

采用宏观分析、化学成分分析、金相检验、断口形貌及能谱分析、硬度测试等方法,对金属冲击试样缺口拉床用的拉刀崩齿断裂进行分析。结果表明:拉刀材料中含有氧化物和硫化物等非金属夹杂物,降低了拉刀的韧性和冷热加工性能。由于拉床无设置过载即时停机保护装置,拉刀在切削高硬度合金钢时瞬时过载发生崩齿断裂,致使大部分刀齿断裂而报废。

By means of adopting macro examination,chemical compositions analysis,metallographic examination,fracture analysis,energy spectrum analysis and hardness testing and so on methods,analyzes the failure forms of the broaches on metal impact notch broaching.The results show that,non-metallic inclusions such as oxide and sulfide in broach material will reduce toughness as well as cold and hot processing performance of the broaches.Because the broaching machine have not a kind of preventing device to transient overload,when it is used to cut high hardness alloy steel,the most teeth of the broach fractured,thereby they could not be used again.