titanium alloy
Titanium forgings
The forging temperature of the titanium is based on the beta phase phase, and is generally selected to select a rough forging at a β region higher than the β-point 50 to 150 ° C. Precision forging is performed at a α + β region below β-point 50 to 150 ° C, and since titanium is easily oxidized, forging is performed at a high temperature, there is no forging temperature as much as possible without forging cracks. In order to obtain high strength and ductility, precise forging in the α + β area should be controlled, and the forging temperature should be controlled, and the heating time is reduced and the forging ratio should be controlled, and the heat generation should be avoided as much as possible, and the heat generated during the forging process is generated. Ensure the ideal forging ratio and excellent titanium alloy properties.
Deformation and deformation resistance of titanium forgings
Certain titanium alloy forgings can be low, for example, α alloy Ti-5Al-2.5 SN, near α alloy Ti-8Al-1Mo-1V, so the forging temperature range is narrow, so this alloy must be repeatedly heated.
Almost all of the titanium alloys are lower than the low temperature area of the β transition point, and the resistance to deformation has increased dramatically. The most representative Ti 6 Al 4 V alloys, although there is good ductility, but at the β phase change point below this region temperature, anti-deformation is still rapidly improved. Further, the anti-modification of the titanium alloy is affected by the strain rate. The faster the deformation, the greater the deformation resistance. Therefore, in the titanium alloy precision forging process, the forging speed is slowed in a narrower forging temperature range.
Forging heating method
Titan forging heating furnaces and other metal materials heating furnaces have a lot of common. The difference is that the thermal conductivity of titanium is low, so he will be heated for a long time. Further, in order to prevent the occurrence of thermal oxidation and hydrogen absorption, when heating in the gas stove, the stainless steel material should be used to prevent the flame directly to heat the titanium furnace. For new furnaces or long-term furnaces, it should be combusted in a dry furnace before use.
Titanium forged classification
Titanium forging includes forging processes, forging methods, forging equipment and forging temperatures. Forging methods are mainly based on the shape, microstructure and mechanical performance requirements of the product.
Square forging
In order to processes titanium ingots into forging and rolling products, blank forging should be carried out. Due to the large size and low deformation capability of the titanium ingot, cracks are prone to cracks during the forging process. Therefore, in the initial stage of forging, heating must be carried out in the β area, then forging, so that the coarse tissue of the central portion of the ingot is thinned. After grain refinement, then processed to a low temperature zone (α + β region) for heating and forging. The most important thing in billet forging is that the shape variable is large, and the casting tissue is not easy to crack. Conversely, since the center portion of the material and the uneven distribution of the surface, in the repeated forging operation, the deformation of the blank is small, and the microcrack is easy to occur. During the billet forging, free forging is usually used.
2. Free forge forging
Before, the anvil should be preheated at 150 ~ 250 ° C. The blank and slab can be improved in β to α + β region, and the tissue forging products can be improved. Although the accuracy and yield of free forging are low, the cost of metal molds can be saved. Suitable for products with a simple shape, a titanium rod, titanium ring, etc. Large forging products can use the same equipment as the slab, and small products can use 0.5 ~ 2T forging equipment.
3. Dimension forging
Dimensions are the process of precisely forging the specific shapes and sizes of the titanium genk or small billet to a particular shape. Typically, the die forging is carried out under low temperature (α + β zone). Although die forging can increase dimensional accuracy and yield, because of the high mold production cost, it is more suitable for batch production of complicated forgings, such as aircraft parts, car parts, and steam turbine blades.
Choice of the die forging device: larger size blank can select 1500 ~ 8000T oil pressure (or hydraulic) machine; the small billet can use the forged hammer of L ~ 4 T. Since the forging forging forging hammers produces greater kinetic energy, it must be taken to prevent overheating caused by hot forging.
4. Rotate the booties
Titanium alloy large ring products can be forged by a rotating forging process, thereby reducing the contact area and rotary forging of the forgings and molds.
5. Constant temperature forging
During the constant temperature forging, the mold and forgings maintain the same temperature at low speed machining. The anti-deformation ability of the forgings is low, and a uniform forgings can be obtained. Moreover, the massive forging processing load is only 1 / 5~1 / 8 of ordinary forging load, but the cost is too high, so there is no extensive application.
Details:
Titanium and Titanium Alloy Forgings
Grade:
GR.1, GR.2, GR.3, GR.4, GR.5 (Ti-6Al-4V), GR.7 (Ti- 0.12~0.25Pd), GR.9(Ti-3Al-2.5V) , GR.12(Ti-0.3Mo-0.8Ni),
T35, T40, T50, T60, TA6V, 3.7024, 3.7034, 3.7055, 3.7064, 3.7164, 3.7165
Standards:
ASTM B348/ ASTM B381/ AMS 4928 and other standards.
Process:
Titanium Sponge- Compacting Electrodes- Double VAR Melting-UT testing- Peeling and Cutting- Ingots-Forging- Billets- Rolling/Precisely Forging- Annealing- Machining-UT testing- Polishing/Grinding- Inspection/Testing- Packing.
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