The production process of flange machining is mainly divided into forging, casting, cutting, and rolling.
Flange Casting and Flange Forging Introduction
The shape and size of the flange blank are accurate, the processing quantity is small, and the cost is low, but there are casting defects (pores). Crack. Inclusion); Poor streamlining of the internal structure of the flange casting (even worse in the case of cutting parts); Forged flanges are generally lower in carbon than cast flanges and are not easy to rust. The forging flanges are streamlined and compact in structure, and their mechanical properties are better than cast flanges. Improper forging flanges process will also appear grain size or uneven, hardening crack phenomenon, forging flange cost is higher than casting flange. Forgings can withstand higher shear and tensile forces than flange castings.
The advantages of flange castings are that they can be produced in a more complex shape and at a lower cost. The advantage of industrial forging is that the internal structure is uniform, and there are no harmful defects such as pores and inclusions in the casting; The difference between casting flange and forging flange from the production process flow, such as centrifugal flange is a kind of casting flange.
Centrifugal flanges are produced by the precision casting method. Compared with ordinary sand casting, the casting structure is much thinner and the quality is improved a lot. It is not easy to have problems such as loose structure, pores, and trachoma.
First of all, we need to understand how the centrifugal flange is produced, the centrifugal casting production of flat-welded flange technology and products, its characteristics is that the product is processed through the following process steps:
①The selected raw materials are put into the medium-frequency electric furnace for melting so that the temperature of molten steel reaches 1600-1700℃;
②Preheat the metal mold to 800-900℃ and maintain a constant temperature；
③Start the centrifuge, step ① the molten steel is injected into the step ② the metal mold is preheated；
④The casting is naturally cooled to 800-900℃ for 1-10 minutes;
⑤Cooling with water to near room temperature, remove the mold and take out the casting.
YIJIN Takes You to Understand the Production Process of Forging Flange
The forging process is generally composed of the following procedures, that is, select high-quality billet blanking, heating, forming, and after forging cooling. Forging techniques include free forging, die forging, and fetal forging. Production, according to the size of the forging quality, the number of production batches choose different forging methods.
Free forging has low productivity, large flange machining allowance, simple tools, and large generality, so it is widely used in free forging single and small batch forgings with simple shapes. Free forging equipment includes air hammers, steam-air hammers, hydraulic press, etc., which are suitable for small, medium, and large forgings production. High die forging productivity, simple operation, easy to realize mechanization, and automation. The size precision of die forgings is high, the flange machining allowance is small, the fiber distribution of forgings is more reasonable, and the service life of the machined parts can be improved further.
The Basic Process of Free Forging
In free forging, the shape of the forgings is gradually forged from the blank through a number of basic deformation procedures. The basic procedures of free forging include upsetting, drawing, punching, bending, and cutting.
1. Upsetting—Upsetting is the operation process of forging the raw material along the axial direction to reduce its height and increase its cross-section. This process is often used for forging gear blanks and other disk-shaped forgings. Upsetting is divided into all upsetting and local forging two kinds.
2. Drawing out—Pull out the length of the billet to increase the length of the forging process, the section is reduced, usually used to produce shaft blank, such as lathe spindle, connecting rod, and so on.
3. Punching—Forging process in which through or through-holes are punched out of the blank.
4. Bending—A forging process in which billets are bent to an Angle or shape.
5. Torsion—Forging process in which one part of the blank rotates at a certain angle relative to another machined part.
6. Cutting—Forging procedure for dividing billet or cutting head.
Die forging is called model forging. It is formed by placing a heated blank in a forging die fixed on the die forging equipment.
The basic process of die forging process: blanking, heating, pre-forging, final forging, punching even skin, edge cutting, tempering, and shot peening. Commonly used processes are upsetting, drawing, bending, punching, and molding.
Commonly used die forging equipment is commonly used die forging hammer, hot die forging press, flat forging machine, and friction press.
Generally speaking, forging flange quality is better, generally through die forging production, crystal structure fine, high strength, of course, the price is also more expensive.
Whether casting flange or forging flange belongs to the common manufacturing method of plate flange. It depends on the strength requirements of the machining parts needed to be used. If the requirements are not high, you can also choose turning flange casting.
Cutting System of the Flange
The disc with the inner and outer diameter and thickness of the flange stamping is directly cut out on the middle palate, and then the bolt hole and waterline are processed. The machining flanges produced in this way are called cut flanges whose maximum diameter is limited to the width of the middle plate.
The process of cutting the slivers with the middle palate and then rolling them into a circle is called coiling, which is mostly used in the production of some large flanges. After successful coiling, it is welded, then flattened, and then processed with waterline and bolt holes.