Forging vs Casting: Analyzing the Core Differences in Performance Advantages of Forging Processing

Forging vs Casting: Analyzing the Core Differences in Performance Advantages of Forging Processing

Dalian forging and casting, as the two core processes of metal forming, have essential differences in performance. Forging relies on "plastic deformation to reshape the structure" as its core, while casting relies on "liquid forming to fill the cavity". The different process paths have created significant advantages in key performance of forged parts.

The material density is the intuitive difference between the two. During the casting process, the metal liquid is prone to forming pores and shrinkage porosity due to gas escape during cooling, resulting in a density typically ranging from 92% to 95%; And forging compresses and welds these defects through external compression (hot forging pressure can reach 3000 tons), increasing the density to over 99.5%. This difference is directly reflected in the hydrostatic test: the cast hydraulic valve body may experience leakage at a pressure of 20MPa, while the forged valve body can still maintain sealing at 35MPa, making it more reliable in high-pressure pipeline systems.

The directional differences in mechanical properties highlight the advantages of forging. The grain size of castings is randomly distributed, and their mechanical properties exhibit anisotropy (with a strength difference of up to 20% in different directions); Forging arranges grains along the direction of force through metal flow, forming a "fibrous structure". Taking automobile connecting rods as an example, the tensile strength of forged parts is 30% higher than that of cast parts, and the fatigue resistance is improved by 50%. It can still maintain stability under millions of cycles of engine impact - data from a certain car company shows that after using forged connecting rods, the engine failure rate decreased by 62%.

In terms of structural integrity, forging can eliminate internal defects that are difficult to avoid in casting. During the casting process, uneven wall thickness is prone to stress concentration, while forging achieves uniform internal structure of the material through integral shaping, avoiding common problems such as cracks and inclusions in castings. On large components such as wind turbine spindles, the fracture toughness (KIC value) of forged parts is 40% higher than that of cast parts, which can withstand sudden loads under extreme working conditions and reduce the risk of complete machine shutdown.

In addition, the processing adaptability of forged parts in Dalian is better. Due to its high density, it is less prone to "edge breakage" during cutting, and the tool life is extended by 20%; However, due to internal looseness, castings are prone to burrs during processing, which increases the subsequent polishing process. Although the initial cost of forging is 15% -20% higher than casting, its lifespan is 3-5 times longer than that of castings under high-pressure, high impact, and high fatigue conditions (such as aviation engines and mining machinery), and its overall cost-effectiveness is actually higher.