The difference between forgings and castings

First, the difference in mechanical properties.

Forgings after secondary processing DU, there will be a hardening process, zhi this process will lead to the arrangement of fine, machine dao mechanical properties without directionality, better than casting.

Two, molding method difference.

The casting is poured into the model after melting the data with good ratio in the melting furnace, and then cooled and formed. Forgings are formed by repeated limiting under pressure effect by a press.

Three, different materials.

Casting parts: directly cast by molten steel, grain size is poor and rough, metal density is slightly low, mechanical stability is poor; Gear forgings: high temperature forging after casting, fine grain size, slightly higher density, stable mechanical properties.

Five, from the non-processing appearance investigation.

Casting pieces are small particles, can see the seam (casting grinding tool cover mouth); Free forging, casting after the appearance of black, slightly flake appearance, can see the casting tucks; Die forging, at first glance, and casting parts are somewhat similar, but the appearance of the granular is still delicate contrast. And die forging is often to do small parts, large parts are difficult to do.

Six, from the processing surface investigation.

Cast iron is significantly different from forgings. Cast iron has no luster on the surface (it will still shine after grinding). Chip chips are broken chips, and gray cast iron will have powder chips. The casting steel processing surface and forging processing surface themselves think that there is no significant difference, both have gloss.

Seven, from the appearance of the two to distinguish.

The surface of the casting is coarse, and there is segregation and shrinkage, while the surface of the gear forging is smooth and shiny. Because gear forgings are forged by external forces, while castings are solidified.