Do you know what the heat treatment process of forgings is like?

Forging is a common forging processing method, which refers to the workpiece or blank obtained by deforming the metal blank after forging, and applying pressure to the metal blank to make it plastically deform and change its mechanical properties. So what is the heat treatment process for forgings? Next, Brishine United Industry Co., Limited. Let me introduce to you, the ways are as follows.

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1. Reasonable selection of deformation temperature and deformation speed

Reasonable selection of the deformation temperature and deformation speed during deformation ensures that the metal has good plasticity during forming, which is very important for plastic forming. If the selected deformation temperature is too high, it is easy to overheat the deformed metal and cause coarse grains. If the selected temperature is too low, work hardening will occur when the metal is deformed, which will increase the deformation resistance, reduce the plasticity of the forging metal, and cause deformation and cracking in severe cases. For materials with high deformation speed sensitivity, the deformation speed should be selected reasonably. In general, the deformation speed of hammer equipment is the highest, the deformation speed of hydraulic press is the lowest, and the deformation speed of press is between the two. For example, the forging of magnesium alloys is suitable for presses. If you want to die forging on a hammer, it is best to tap lightly at the beginning, and gradually increase the degree of deformation of each hammer during forging as the groove is filled.

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2. Reasonable selection of deformation methods

The choice of deformation mode directly affects the plastic flow and stress state of the deformed body in the cavity. For example, the more the number of compressive stress the billet bears during deformation, the better its plasticity will be. Therefore, during plastic deformation, for materials with low plasticity, some measures can be taken to increase the three-dimensional compressive stress state to prevent the billet from cracking. For example, when upsetting, a movable collar or wrapping can be used to facilitate forming, and when drawing, using anvil to draw is conducive to forming and improves drawing efficiency.

3. Improve the uniformity of material composition and organization

The chemical composition and structural properties of alloy ingots are very uneven. High temperature diffusion annealing can be carried out before plastic working to make the structure and composition of the ingot uniform, which can improve the plasticity of the material. For example, magnesium alloy MA3 is subjected to high temperature homogenization treatment at 400 ° C for 10 hours, and the compression deformation degree on the press can reach more than 75%, but if high temperature homogenization treatment is not carried out, the allowable deformation degree is only about 45%. For high alloy steel ingots, depending on the composition of the forgings, it can be kept for a long time in the temperature range of 1050-1150 ℃ or even higher, and good results can also be obtained. Due to the long production cycle and high cost of high temperature homogenization treatment, it can be replaced by appropriately extending the holding time during forging heating. The disadvantage is that the productivity is reduced, and coarse grains should be avoided.

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4. Reduce the degree of uneven deformation

Uneven deformation will cause additional stress, which will reduce the plasticity of the billet and promote the generation of cracks. The measures that are often used to reduce uneven deformation are: reasonable operating specifications, good lubrication, appropriate tool and die shape, etc. can reduce the uneven deformation. For example, when drawing for a long time, select the appropriate feed amount. If the feed amount is too small, it may cause the blank center to be forged, resulting in additional stress, and in severe cases, core cracks; Upsetting such as metal gaskets is beneficial to reduce the drum shape of the blank and prevent cracks on the surface.