The processing property of metal refers to the possibility or difficulty of obtaining qualified products in the cold or hot manufacturing process of mechanical parts, that is, the ability of materials to adapt to the practical production process requirements. Different processing conditions lead to different processing methods and product properties, such as casting, forging, deep drawing, bending, cutting, weldability, hardenability, etc. Process performance is often determined by a combination of complex factors (physical, chemical, mechanical ans so on).
The ability of metal materials to obtain qualified workpieces by casting which measured by fluidity, shrinkage and segregation. Fluidity is the ability of liquid metal to fill a mold. Shrinkage refers to the degree of volume shrinkage during solidification and segregation refers to the inhomogeneity of chemical composition and structure in metal due to the difference of crystallization sequence in the process of metal cooling and solidification.
It refers to the metal material can change the shape without crack performance in the pressure processing, that is the capacity, in the hot or cold environment, metal can be hammer forging, rolling, stretching, extrusion and other processing. Malleability is mainly related to the chemical composition of metal materials.
Machinability refers to the difficulty to become qualified workpieces in the cutting process. Machinability is often measured by the surface roughness, the allowable cutting speed and the abration of tool. This is not only related to the chemical composition and mechanical properties itself, but also related to the cutting process (like tool geometry, durability, cutting speed and feed quantity, etc.). Although there are many factors affecting the cutting performance, but the most important is the nature of the metal itself, especially the hardness, when the metal hardness of HB150~230, the best cutting performance.
Weldability refers to the adaptability of metal materials to welding processing, that’s the performance of obtaining qualified welded joints under specified welding conditions. It related to metal welding defect sensitivity and the performance welding joints to meet the use requirements under a certain welding process conditions.
- Heat treatment
Metal heat treatment is to heat the metal workpiece to the appropriate temperature for a certain time and then cooling at different speeds in different media, by changing the surface or internal microstructure of metal materials to control its performance of a process. Heat treatment mainly includes annealing, normalizing, quenching, tempering, tempering, chemical heat treatment, solid solution treatment, precipitation hardening (precipitation strengthening), aging treatment and so on. The heat treatment performance of steel mainly considers its hardenability(quenching can get higher hardness and smooth surface), containing manganese, chromium, nickel and other elements of alloy steel hardenability is better while carbon steel hardenability is poor. The heat treatment requirement of aluminum alloy is strict and only several kinds of Copper alloy can be strengthened by melting heat treatment.