The Machinability of Metal

The machinability of metal materials usually refers to a kind of performance or quality that can be clearly defined and measured as a sign of its machinability. Generally speaking, good machinability should be: good tool durability or high cutting speed under a certain durability, low cutting force, low cutting temperature, easy to obtain good workpiece surface quality and chip shape, easy to control or easy to break chips.

The concept of machinability of materials is relative. The so-called good or bad machinability of a material is relative to another material. Generally, when discussing the machinability of steel, it is customary to take carbon structural steel 45 as the reference. For example, high strength steel is difficult to process, which is relative to 45 steel.

The cutting performance of the tool is most closely related to the machinability. The machinability of the machined material can not be discussed in isolation from the cutting performance of the tool, but should be studied together. After understanding the machinability of workpiece materials and taking effective measures, we can improve machining efficiency, ensure machining quality and reduce machining cost.

Main indexes for evaluating machinability of workpiece materials

The machinability of a material is the difficulty of guiding the machinability of a material. Its ease is generally related to the chemical composition, heat treatment state, metallographic structure, physical and mechanical properties and cutting conditions of the material.

The machinability of workpiece materials is usually measured by one or more of the following indicators:

1. Measured by tool life

The allowable cutting speed for cutting a workpiece material on the premise of ensuring the same tool durability;

2. Measured by machining quality such as surface finish

3. Measured by unit cutting force

4. Measured by the ultimate metal removal rate

5. Measured by chip breaking performance, including chip shape