1、 Differences in mechanical properties.
After the second machining, there will be a hardening process, which will lead to the arrangement of fine Dao density, no directionality of mechanical properties, better than the casting.
2、 Forming method difference.
The casting is melted by smelting furnace, poured into the model, cooled and formed; the forging is composed of repeated restriction by press under the pressure effect.
3、 Different materials.
Casting: it is composed of direct casting of molten steel, with poor rough grain size, slightly low metal density and poor mechanical stability; gear forging: it is composed of high-temperature forging after casting, with fine grain size, slightly high density and stable mechanical performance.
4、 Investigation from unprocessed appearance.
The casting piece is in the shape of small particles, and the drape seam can be seen (casting grinding tool closing cover); after free forging, the surface is black after casting, and the surface is slightly called flake, and the casting pleats can be seen; die forging, at first glance, is similar to the casting piece, but the appearance of particles is still relatively fine. And die forging is often done small parts, large parts difficult to do.
5、 Investigation from machined surface.
There are significant differences between cast iron and forgings. The surface of cast iron is not glossy (it will still be shiny after grinding), the chips of chips are broken, and the gray cast iron will have powder chips. There are no significant differences between the cast steel processing surface and the forging processing surface, both of which have glossiness.
6、 Distinguish the two from their appearance. |