Forging process parameters are core control indicators for ensuring the quality, microstructure, and production efficiency of forgings. Depending on the process type and equipment conditions, common forging process parameters mainly include the following categories:

1. Forging Temperature Related Parameters

Temperature control is fundamental to forging, directly affecting the material's plasticity and deformation resistance.

1) Initial Forging Temperature: This refers to the surface temperature of the billet at the start of forging, ensuring the metal has good plasticity. For example:

* Carbon steel: generally 1100–1250℃

* Aluminum alloys: between 350–500℃

2) Final Forging Temperature: This refers to the lowest temperature at the end of forging, which must be 50–100℃ higher than the metal's recrystallization temperature to ensure a refined microstructure after forging.

* The final forging temperature for carbon steel forgings is typically no lower than 727℃ (recrystallization temperature).

* Alloy steel forgings can be as low as 200–300℃.

3) Heating Temperature Range: Determine a reasonable range based on the iron-carbon phase diagram or material properties to avoid overheating or burning.

2. Deformation-Related Parameters: These parameters directly determine the density of the internal structure of the forging and the effect of defect annealing.

1) Anvil Width Ratio (W/H or b/h): Defined as the ratio of the anvil width to the height of the forging before deformation, it is a key parameter affecting the core stress state.

* WHF method requires an anvil width ratio of 0.68–0.77.

* LZ forging method recommends 0.8–0.9.

* New FM method requires ≥0.4.

2) Billet Width Ratio (B/H or b/h): The ratio of the billet width to its height, used to optimize stress distribution during the drawing process.

* LZ method recommends a reduction rate between 0.85 and 1.18.

* New FM method recommends 0.83 to 1.20.

3) Reduction Rate: The degree of deformation per forging pass, usually expressed as a percentage.

* WHF method requires a reduction rate of at least 20% per pass.

* FM method recommends 14%–15%.

4) Forging Ratio: Represents the total degree of deformation, calculated as the ratio of the billet cross-sectional area to the forging cross-sectional area.

* For general structural parts, the forging ratio is 3:1 to 5:1.

* For large aerospace forgings, it can reach 6:1–8:1.

5) Feed Rate and Overlap:

* The feed rate should reach 70%–90% of the anvil width to ensure through forging.

* There should be approximately 10% anvil width overlap between the two reduction zones to prevent incomplete forging.

3. Forging Equipment and Operating Parameters: Reflect the dynamic control level of the forging process.

1) Impact Energy or Pressure: Determined by the tonnage of the forging equipment. For example, hydraulic presses of 40MN and above are often equipped with a master manipulator for precise control.

2) Deformation Rate/Speed: Affects material flow characteristics:

* Low-speed forging is suitable for complex shapes, reducing the risk of cracking.

* High-speed forging is suitable for mass production of simple parts.

3) Lubrication and Die Condition: Die surface lubrication reduces frictional resistance and improves filling capacity, which is especially crucial in die forging.

4. Special Process Parameters (Classified by Method)

* Forging Method Key Process Parameters

1) WHF Method: Anvil width ratio 0.68–0.77, reduction rate ≥20%, heating temperature 20–30℃ higher than conventional methods.

2) FM Method: Upper anvil width ratio 0.6, reduction rate 14%–15%.

3) LZ Method: Anvil width ratio 0.8–0.9, material width ratio 0.85–1.18, avoiding bidirectional tensile stress.

4) NJTS Method: When the anvil width ratio b/h₀ ≥ 0.8, the void closure effect is significantly improved.

5) SUF Method: Anvil width ratio w/h ≥ 0.52 can effectively forge defects.