In the initial stage of forging deformation of flat welded flange, the porous preform is easy to deform and the deformation force is small, and the density increases rapidly. In the later stage of forging, since most of the pores are closed, the deformation resistance is increased, and the deformation force required to eliminate the residual pores is rapidly increased. The deformation resistance is closely related to the deformation temperature, and the higher deformation temperature is conducive to compactness and reduce the deformation resistance. The higher deformation speed also contributes to the compactness of the flat welded flange.
The flat welding flange forging process requires strict equipment than the conventional die forging. The displacement characteristics of the punch must match the deformation and compactness of the preform. The contact time between the blank and the mold should be as short as possible. The forging press should have good rigidity, and the movable beam and the piston should have good guiding precision to ensure the forging accuracy. Therefore, the flat welding flange forging generally selects a mechanical press, such as a crank press, or a higher precision friction press.
First, the characteristics of flat welding flange
The flat welded flange not only saves space, reduces weight, but more importantly ensures that the joint is not leaked and has good sealing performance. The reduced size of the compact flange is due to the reduced diameter of the seal which will reduce the cross-section of the seal face. Second, the flange gasket has been replaced by a seal ring to ensure that the seal faces the sealing surface. As the required pressure is reduced, the size and required number of bolts can be reduced accordingly, so a new design that is small in size and light in weight (70% to 80% lighter than conventional flanges) is designed. product. Therefore, the flat welding flange type is a relatively high quality flange product, which reduces the quality and space and plays an important role in industrial use.
Second, flat welding flange technical parameters:
(1) Flange outer diameter: 75mm-2190mm
(2) Bolt hole center circle diameter: 50mm----2130mm
(3) Bolt hole diameter: 11mm-30mm
(4) Number of bolt holes: 4 - 48
(5) Thread: M10-M27
(6) Flange thickness: 12mm-58mm
(7) Pipe outer diameter: A (17. 2-2032MM) B (14-2020MM)
(8) Flange inner diameter: A (18-2036MM) B (15-2024MM)
(9). Theoretical weight of flange: 0.36kg--234.6kg (DN1800)
(10). Material: A105, 20#, Q235, 16Mn, 304, 304L, 316, 316L, 321
(11). Production standards: HG/T20592-2009, GB/T9119-2000, SH3406-1996, JB/T81-1994, DIN 2573, DIN 2576, EN1092-1
Product name plate flat welding flange
Working pressure PN0.25MPa, PN0.6MPa, PN1.0MPa, PN1.6MPa, PN2.5MPa
Product Category Full Flat Flange (FF), Panel Flange (RF)
Manufacturing materials 304 316 304L 316L 321 2025Q23516MN, etc.
Connection form Single-sided welding, double-sided nut connection.
Product features beautiful appearance, smooth surface, acid and alkali resistance, anti-corrosion, strong texture
Third, the flat welding flange forging method
Forging of flat welded flanges can be divided into free forging, upsetting, extrusion, die forging, closed die forging, and closed upsetting. Closed die forging and closed upset forging have high material utilization due to the absence of flash. Finishing of complex forgings is possible with one or several processes. Since there is no flash, the area of ​​force applied to the forging is reduced and the required load is also reduced. However, care should be taken not to completely limit the blank. To this end, the volume of the blank is strictly controlled, the relative position of the forging die is controlled, and the forging is measured to reduce the wear of the forging die.
According to the movement mode of the forging die, forging can be divided into pendulum, pendulum swivel, roll forging, cross wedge rolling, boring ring and cross rolling. Swing, swivel and shackle can also be used for precision forging. In order to improve the utilization of materials, roll forging and cross rolling can be used as a front-end process for slender materials. The same rotary forging as free forging is also partially formed, which has the advantage that it can be formed in the case of a smaller forging force than the forging size. This type of forging, including free forging, expands from the vicinity of the mold surface to the free surface during processing. Therefore, it is difficult to ensure accuracy. Therefore, the movement direction of the forging die and the swaging process can be controlled by computer. The forging force obtains products with complex shapes and high precision. For example, forgings such as steam turbine blades with a large variety and large size are produced.
When the temperature exceeds 300-400 ° C (blue fragile zone of steel), reaching 700-800 ° C, the deformation resistance will be drastically reduced, and the deformation energy is also greatly improved. According to the forging in different temperature regions, for the forging quality and the forging process requirements, it can be divided into three forming temperature zones: cold forging, warm forging and hot forging. There is no strict limit to the division of such temperature regions. Generally speaking, forging in a temperature region where recrystallization is performed is called hot forging, and forging at room temperature is called cold forging.
In the case of low temperature forging, the dimensional change of the forging is small. Forging at 700 ° C or less, the formation of scale is small, and there is no decarburization on the surface. Therefore, as long as the deformation can be in the forming energy range, cold forging is easy to obtain good dimensional accuracy and surface finish. As long as the temperature and lubrication cooling are controlled, warm forging below 700 °C can also achieve good precision. In hot forging, since the deformation energy and deformation resistance are small, large forgings with complicated shapes can be forged. For high-precision forgings, hot forging can be performed in the temperature range of 900-1000 °C. In addition, attention should be paid to improving the working environment of hot forging. Forging die life (hot forging 2-5 thousand, warm forging 1-2 million, cold forging 2-5 thousand) is shorter than forging in other temperature ranges, but it has a large degree of freedom and low cost .
The billet is deformed and hardened during cold forging, so that the forging die is subjected to high loads. Therefore, it is necessary to use a high-strength forging die and a hard lubricating film treatment method for preventing wear and adhesion. In addition, in order to prevent cracking of the billet, intermediate annealing is performed as needed to ensure the required deformability. In order to maintain a good lubrication state, the billet can be phosphatized. At the time of continuous processing with bar stock and wire rod, the section cannot be lubricated at present, and the possibility of using a phosphating lubrication method is being studied.
Hydraulic Adapter,Hydraulic Fitting Adapter,Metric Hydraulic Adapters,Lawson Hydraulic Adapter
Hydraulic Fitting,Threaded Adapter Co., Ltd. , http://www.xindawind.com