Due to the high pressure, the life of titanium rods is reduced. Therefore, when closed die forging is used to forge titanium rods, the volume of the original blank must be strictly limited, which complicates the material preparation process. Whether to use closed die forging should be considered from the perspectives of interest and process feasibility. In open die forging, the burr loss accounts for 15%-20% of the blank weight. The process waste of the clamping part (if this part must be left according to the die forging conditions) accounts for 10% of the blank weight. The relative loss of burr metal usually increases with the decrease of the blank weight. For some forgings with asymmetric structures, large cross-sectional area differences, and local parts that are difficult to fill, the burr consumption can be as high as 50%. Although there is no burr loss in closed die forging, the blank making process is complicated and more transition tool grooves need to be added, which will undoubtedly increase the auxiliary cost.
The last blank is only heat treated and cut. Forging temperature and degree of deformation are the basic factors that determine the alloy structure and performance. The heat treatment of titanium rods is different from that of steel. Die forging is usually used to make shapes and sizes close to scrap. It does not play a decisive role in the organization of the alloy. Therefore, the process specifications of the last step of titanium rods play a particularly important role. The overall deformation of the blank must not be less than 30% and the deformation temperature must not exceed the phase transition temperature. In order to make the titanium rod obtain higher strength and plasticity at the same time, the temperature and deformation degree should be distributed as evenly as possible in the entire deformed blank.
Po rekristalizaciji toplotni obdelavi % 2c enakomernost titan palice in zmogljivost ni kot dobro kot to od jekla odkovkov. V območju e2% 80% 8b % e2 % 80 % 8 b intenzivna kovina pretok % 2c nizka povečava je mehka kristal % 2c in visoka povečava je enakomerna fina kristal % 3b v težka deformacija območje % 2c zaradi majhna deformacija ali ne deformacija % 2c njena organizacija pogosto ohranja stanje pred deformacijo. Torej, ko kovanje nekaj pomembno titan palica deli (kot kompresor diski, rezila, itd.), v dodatku za nadzor deformacija temperatura spodaj TB in primerna deformacija raven, it je zelo pomembna za nadzor organizacija originala prazno. V nasprotnem primeru, grobo zrnato organizacija ali nekaj napake bo podedovane v kovanje, in nazaj toplotna obdelava ne more biti odpravljena, ki bo pripeljala do razreza kovanja kovanja bo pripeljala do razreza kovanja.
In the area of rapid deformation where the thermal effect is locally concentrated, when forging titanium rod forgings with complex shapes on the hammer. Even if the heating temperature is strictly controlled, the temperature of the metal may still exceed the TB of the alloy. For example, when forging a titanium bar blank with an I-shaped cross section, the hammer is too heavy, and the local temperature in the middle (web area) is about 100 degree higher than the local edge due to the deformation heat effect. In addition, the hard-to-deform area and the area with a critical deformation level are prone to form coarse-grained structures with relatively low plasticity and durability during the heating process after forging. Therefore, the mechanical properties of forgings with complex shapes forged by hammer forging are often very unstable. However, it will lead to a sharp increase in deformation resistance. Although reducing the heating temperature for forging can eliminate the risk of local overheating of the blank, it will increase tool wear and power consumption, and it is necessary to use more powerful equipment.
The use of multiple light tapping methods can also reduce the local overheating of the blank. However, this requires increasing the heating times. To compensate for the heat lost by the blank in contact with the colder die. And when the requirements for the plasticity and durability strength of the deformed metal are not too high, it is better to use hammer forging for forgings with relatively simple shapes. However, alloys should not be hammer forged, because multiple heating during the die forging process will have a favorable effect on the mechanical properties. Compared with the forging hammer, the working speed of the press (hydraulic press, etc.) is greatly reduced, which can reduce the deformation resistance and deformation thermal effect of the alloy. When the titanium rod is die forged on the hydraulic press, the unit die forging force of the blank is about 30% lower than that of the hammer die forging, which can increase the life of the die. The reduction of thermal effect also reduces the risk of metal overheating and temperature rise exceeding TB.
Pod isto enoto tlak kot kovanje kladivo matrica kovanje % 2c ko je stiskalnik je matrica kovana. prazno ogrevanje temperatura se lahko zmanjša za 50100 stopinj . Na to način, interakcija med segreto kovino in periodično plin in temperatura razlika med blank in matrica so tudi zmanjšane skladno, s temi izboljšanje enakomernost deformacija, enakomernost struktura matrica kovanje je tudi super izboljšano, in konsistence mehanskih lastnosti je tudi izboljšano primerno. Zmanjšaj deformacija hitrost, številčna rast več očitna površina krčenje, površina krčenje je bolj občutljivo na strukturno napake povzročeno pregrevanje.
The friction with the tool is large and the contact surface of the blank cools too quickly. To improve the fluidity of the titanium rod and increase the life of the die. The usual practice is to increase the die forging slope and fillet radius and use lubricants: the height of the burr bridge on the forging die is larger than that of steel. The characteristic of titanium rod deformation is that it is more difficult to flow into a deep and narrow die groove than steel. This is because titanium has high deformation resistance. It is generally about 2mm larger. Sometimes, burr grooves with uneven bridge size can be used to limit or accelerate the flow of metal to a certain part of the groove. For example, in order to make the groove easy to fill. A rectangular box-shaped forging (as shown in Figure 12) has thinner front and rear side walls; thicker left and right side walls. When the burr grooves shown in B-B are used around the box-shaped part, due to the small resistance of metal flowing into the left and right side walls, the metal has difficulty flowing to the thinner front and rear side walls and cannot be filled. Later, the front and rear side walls still use the burr grooves shown in B-B, while the left and right side walls use the burr grooves shown in A-A. Due to the wide size of the bridge and the obstruction of the damping groove, the thinner front and rear side walls are completely filled, and the metal is saved compared to the aforementioned burr groove method.
Zagotavlja izvedljivo metodo za reševanje oblikovanje velikih in kompleksnih titan palica natančnost odkovki. Ta metoda je bila široko uporabljena v titanu palici proizvodnji. Eden od več učinkovit načinov za izboljšanje fluidnosti titana palice in zmanjšanje deformacije odpornosti je za povečanje predgrevanje temperaturo matrice. Je sotečeno kovanje in vroče matrice kovanje so bili razviti v preteklih dveh ali treh desetletjih doma in v tujini.
