Carbon steel after oxygen flame cutting, slotted at the heat affected zone hardness away from the slotted at hard cut joints after milling cutting surface of the hard bright, shiny inconsistent; and uniform hardness of forging a whole. consistent surface gloss after milling.

Slotted to the vicinity of the metal hardness, grain structure coarsening phenomenon.

Forging can be formed of fibrous tissue, the fiber distribution and direction; forged microstructure becomes dense and forging state characteristics of the organization; if poor quality of raw materials used in the forging process is unreasonable, it may produce custom forged eyebolts defects include surface defects, internal defects.

Based on the above characteristics, visual addition to the comparative appearance of shiny, with experience in forging milling can also see that the fiber direction, and the cutting feed milling fiber direction.

In addition to visual comparison can also be viewed under a metallurgical microscope. Forging milling organized crime and has the characteristics of forging state organization, there are likely to see the forging of internal defects, while a coarse microstructure can be seen cutting the feed milling.

Cutting of steel plate by milling after heat-affected zone still exists, can be visual to the uneven color of steel, pickling polished under a microscope can show the coarse-grained lattice.

Forged steel plate by milling the surface color is basically the same under a microscope can show the pickling polishing grains fine was the fiber arrangement.