削片机刀片断裂分析

Fracture Analysis of Wood-chip Cutting Knives

从削片机刀片断裂失效断口形貌特征、金相组织、硬度等方面,对削片机刀片的早期断裂失效现象进行了分析,结果表明:该型号削片机刀片的早期断裂属于脆性断裂。断裂失效的主要原因是刀片刀背处局部盐浴高温回火工艺操作不当,致使刀背处硬度过高,韧性降低;同时钢中非金属夹杂物和碳化物的沿晶聚集等也是造成了刀片发生早期断裂的原因。

This article has analysed the phenomenon of early fracture of wood-chip cutting knives, from the looks characteristic of rupturing to lose efficiency, metallographic structure, hardness, etc. The result shows： The early fracture of wood-chip cutting knives is brittle fracture. The main reason is that the high-temperature tempering in the part of cutting knives transit-ion zone in salt bath is operated improperly, causing the hardness of the part of cutting knives transition zone to be too high, and toughness is reduced;Fixing improper, nonmetal inclusion of steel and carbide along crystal are the reason of early fracture of wood-chip cutting knives.