Heat treatment metal characteristics

In the heat treatment process, the metal has opaque, good heat conduction and conductivity with metal luster, and its conductivity decreases with the increase of temperature, which is rich in ductility and expansibility. The following small series will introduce the metal characteristics in the heat treatment process in detail.

1. A solid (i.e., a crystal) in which atoms are regularly arranged;

2. Alloy: material with metal characteristics, consisting of two or more metals or metals and nonmetals;

3. Phase: components with the same composition, structure and performance in the alloy;

4. Solid solution: it is a solid metal crystal with one (or several) component atoms (compounds) dissolved in the lattice of another component, but still maintaining the lattice type of the other component. There are two types of solid solution: interstitial solid solution and displacement solid solution;

5. Solution strengthening: because the solute atoms enter into the gap or node of the solvent lattice, the lattice will be distorted and the hardness and strength of the solution will be increased. This phenomenon is called solution strengthening phenomenon;

6. Compound: a new solid crystal structure with metal properties is formed by the combination of alloy components;

7. Mechanical mixture: the alloy composed of two crystal structures, though two crystal structures, is a component with independent mechanical properties;

8. Ferrite: interstitial solid solution of carbon in α - Fe (body centered cubic iron);

9. Austenite: interstitial solid solution of carbon in γ - Fe (face centered cubic iron);

10. Cementite: stable compound (Fe3C) formed by carbon and iron;

11. Pearlite: mechanical mixture of ferrite and cementite (F + Fe3C contains 0.8% carbon);

12. Ledeburite: a mechanical mixture of cementite and austenite (containing 4.3% carbon).

Heat treatment is one of the important processes in mechanical manufacturing. Compared with other processing technologies, heat treatment generally does not change the shape of the workpiece and the overall chemical composition and metal characteristics.