Surface treatment of forgings（一）

1. Heat treatment

Heat treatment is the process of changing the internal structure and properties of forgings through heating and cooling. Common techniques include:

Quenching: Rapid cooling to improve hardness and strength.

Tempering: Reduce brittleness after quenching and improve toughness.

Normalization: Improve organizational uniformity and enhance overall performance.

Annealing: reduces hardness and improves processing performance.

2. Surface strengthening treatment

Surface strengthening treatment can improve the surface hardness and wear resistance of forgings, and common processes include:

Shot peening treatment: By high-speed spraying of steel shot or glass beads, a compressive stress layer is formed on the surface to improve fatigue strength.

Carbonization: Penetrating carbon into the surface at high temperatures to improve surface hardness and wear resistance, suitable for low carbon steel forgings.

Nitriding: Forming a nitride layer on the surface to improve hardness, wear resistance, and corrosion resistance, suitable for alloy steel forgings.

Induction hardening: Local quenching of the surface through induction heating, suitable for gear and shaft parts.

3. Anti corrosion treatment

Anti corrosion treatment can improve the corrosion resistance of forgings, and common processes include:

Electroplating: Plating a layer of metal (such as chromium, nickel, zinc) on the surface to improve corrosion resistance and aesthetics.

Hot dip galvanizing: immersing forgings in molten zinc to form a zinc layer, suitable for outdoor use of parts.

Chemical plating: Forming a uniform metal coating on the surface through chemical reactions, suitable for complex shaped parts.

Anodizing (applicable to aluminum alloy forgings): forms an oxide film on the surface to improve corrosion resistance and surface hardness.

4. Painting and Coating

Painting and coating treatment can improve the appearance and performance of forgings, and common processes include:

Powder spraying: Powder coating is sprayed by electrostatic spraying, and after heating and curing, it forms a uniform coating, suitable for outdoor equipment.

Paint coating: Use rust proof paint or decorative paint for coating to improve corrosion resistance and aesthetics.

PVD/CVD coating: A hard coating (such as TiN, CrN) is formed on the surface through physical or chemical vapor deposition techniques to improve wear resistance and corrosion resistance.