How does a forge make a high density forgings

Along with the continuous occurrence of our national economy, the use of forgings is more and more widespread, so the forging plant requirements mainly refer to the forging, the size, shape, position and surface precision of the forging, among which the surface precision mainly refers to the surface roughness.


Compared with ordinary die forging, the main advantages of precision die forging are: less machine manufacturing allowance; The dimensional accuracy is higher, that is, the dimensional deviation of precision die forging is smaller than that of ordinary die forging, generally half of the deviation of ordinary die forging, or even small; The surface is very good, that is, the surface roughness of precision die forging is low, the surface pitting and other defects and the residual flying edge width after cutting is strictly restricted.


Compared with cutting manufacturing, the main advantages of precision die forging are: because the shape and size of the blank of forging is close to or even exactly the same as the finished parts, the material utilization rate is high; Because of precision molding, the distribution of metal fibers is consistent with the shape of the parts and continuous compact, so that the mechanical properties of the parts have a great increase, so precision die forging is also called less cutting process.


Forgings in the heat treatment furnace is found to be overheated, can be taken from the overheating temperature to the temperature of air cooling to the disappearance of fire color (about 500 ~ 550℃), and then heated to the specified annealing temperature, forging plant overheated forgings, can use the correct specification for 1 normalizing or annealing, in order to re refine its grain, overheated not serious forgings, can use 1 normalizing; The larger forgings can be used twice normalizing (Ac3+50 ~ 70℃), for more serious overheating forgings, can be used 2 times normalizing, Ac3+100 ~ 150℃; Sub-ac3 +30 ~ 50℃, it is very important to avoid overheating, which requires the selection of appropriate heating temperature and heating and holding time, strictly and correctly implement the heating specification.


The forging plant should overhaul the temperature control meter in time and install the thermocouple correctly to avoid excessive heating temperature. When the forging heating temperature is high to close to the metal melting temperature, then not only the grain coarse, but also cause austenite, serious oxidation of grain boundaries and the melting of low melting point components, destroy the intergrain, so that the forging scrap, this phenomenon is called overburning, the forging factory in the heating process from the steel sparks, The observation of the tissue found that there was melting or oxidation phenomenon along the grain boundary, which could not be used, and the overburned parts could not be remedied, and could only be scrapped.