Forgings need to be uniform from piece to piece, free from porosity, excess space, inclusions, or other defects. The components produced by this method have a high ratio of strength to weight. These components are usually used in aircraft structures.
The advantages of forgings are the extensible length and contractible cross-section; contractible length and extensible cross-section; changeable length and changeable cross-section. The types of forgings are: free forging/hand forging, hot die forging / precision forging, upsetting, rolling forging, and die forging.
1. Aircraft forgings
By weight, about 85% of aircraft components are forgings. Turbine disk, rear journal, blade and wing beam of aircraft engine, rib plate of fuselage, wheel bracket and inner and outer cylinder of landing gear are important forgings related to aircraft safety. Aircraft forgings are mostly made of high strength, wear-resistant, corrosion-resistant aluminum alloy, titanium alloy, nickel base alloy and other valuable materials. In order to save materials and energy, most aircraft forgings are produced by die forging or multi-directional die forging press. By weight, 71.9% of the forgings are made on automobiles. The general automobile consists of 15 parts, such as body, trunk, engine, front axle, rear axle, frame, gearbox, transmission shaft, steering system, etc. For example, the crankshaft, connecting rod, camshaft, front beam, steering knuckle, half shaft, half shaft sleeve and transmission gear in the axle box used in the automobile engine are all key forgings for the safe operation of the automobile.
2. Diesel engine
The diesel engine is a kind of power machinery, which is often used as the engine. Taking a large diesel engine as an example, more than ten kinds of forgings are used, such as cylinder head, main journal, crankshaft flange, output shaft, connecting rod, piston rod, piston head, crosshead pin, crankshaft transmission gear, ring gear, intermediate gear, and oil pump body.
3. Marine forgings
Marine forgings are divided into three categories: main engine forgings, shafting forgings, and rudder forgings. The forging of the main engine is the same as that of a diesel engine. Shafting forgings include thrust shaft, intermediate shaft, stern shaft, etc. Rudder forging includes rudder stock, rudder post, rudder pin, etc.
4. Weapon forging
Forging plays an important role in the weapon industry. By weight, 60% of tanks are forged. The barrel, muzzle brake, and tail of artillery, rifled barrel and three-edged bayonet of infantry weapon, rocket and submarine deep-water bomb launching device, and fixed seat, stainless steel valve body for a high-pressure cooler of a nuclear submarine, shell and cartridge are all forged products. Besides steel forgings, weapons are made of other materials.
5. Petrochemical industry
Forgings are widely used in petrochemical equipment. For example, the manhole and flange of the spherical storage tank, all kinds of tube plates and butt welding flanges required for heat exchanger, the whole forged cylinder (pressure vessel) of the catalytic cracking reactor, the cylinder section used for hydrogenation reactor, and the top cover, bottom cover and head required for chemical fertilizer equipment are forgings.
6. Mine forgings
According to the weight of equipment, the proportion of forgings in mining equipment is 12-24%. Mining equipment: mining equipment, winch equipment, crushing equipment, grinding equipment, washing equipment, sintering equipment.
7. Nuclear forgings
Nuclear power is divided into a pressurized water reactor and a boiling water reactor. The main heavy forgings of the nuclear power plant can be divided into the pressure vessel and reactor internals. Pressure shell includes cylinder flange, nozzle section, nozzle, upper cylinder, lower cylinder, cylinder transition section, bolts, etc. Reactor internals work under severe conditions such as high temperature, high pressure, strong neutron irradiation, boric acid water corrosion, erosion, and hydraulic vibration, so 18-8 austenitic stainless steel should be selected.
