金刚石圆锯片刀头脱落的原因

摘要

某批次金刚石圆锯片在锯切花岗石过程中发生了刀头从锯片基体上脱落的事故，为找到刀头脱落的原因，对刀头脱落处基体的化学成分、显微组织以及断口的宏观、微观形貌进行了分析；对不同热处理批次的金刚石圆锯片在标准锯切参数下进行锯切试验，分析了刀头脱落的主要原因，并提出了改进措施。结果表明：金刚石圆锯片基体75Cr1合金钢的热处理工艺不当，导致基体与刀头的组织和硬度差异明显，使得锯切过程中基体外圆区域发生脆性断裂，从而导致刀头脱落；建议适当延长圆锯片基体的奥氏体化保温时间，必要时可在淬火前增加一道高温退火工序。%In order to find out the reasons of tool bit dropping from diamond circular saw blade substrate during sawing process,the chemical composition,microstructure and fracture appearance of the substrate from where the tool bit dropped off were analyzed.Sawing experiments under standard sawing parameters were performed using diamond circular saw blade heat-treated with different parameters,and the reasons of tool bit dropping was analyzed,some improvement measures were proposed.The results show that the microstructure and hardness of 75Cr1 steel substrate and tool bit had obvious difference due to insufficient heat treatment process,this led to the outer region of the substrate fractured with brittle characteristics during sawing process,and then led to the tool bit dropping from the substreate.Some proposals were given as follows:extending holding time of austenitizing properly and adding high-temperature annealing process before quenching in necessity.