The microstructure and mechanical properties of metals can be improved after forging.Casting organization after forging method of thermal deformation due to metal deformation and recrystallization, make original bulky dendrite and columnar grain to grain is fine and uniform axial recrystallization organization, make the ingot in the original segregation, porosity, porosity, slag compaction and welded, such as its organization become more closely, plasticity and mechanical properties of the metal.
Generally speaking, the mechanical properties of castings are lower than those of forgings of the same material.In addition, the metal forging process can guarantee the continuity of fibrous tissue, the forging of fibrous tissue and forging appearance consistent, metal flow is complete, can guarantee the parts with good mechanical properties and long service life with precision die forging, cold extrusion, extrusion temperature and other process of forging, is incomparable by casting.
1. Aircraft forging
By weight, about 85 percent of the components on an airplane are forgings.The turbine disc of the aircraft engine, the rear journal (hollow shaft), the blade, the wing SPAR of the wings, the fuselage's rib plate, the wheel bracket, and the inside and outside cylinder of the landing gear are all important forgings related to aircraft safety.Aircraft forgings are made of precious materials such as aluminum alloy, titanium alloy, nickel base alloy, etc.In order to save materials and energy, most of the forging parts for aircraft are produced by die forging or multi-direction die forging press.Car forging by weight, the car has 1719% forging.The general car by the body, the car box, the engine, the front axle, the rear axle, the frame, the transmission, the transmission shaft, the steering system and so on 15 parts constitute the automobile forging parts characteristic is the appearance is complex, the weight is light, the working condition condition is poor, the safety degree request is high.For example, the crankshaft, connecting rod, camshaft used in automobile engine, the front beam, steering knuckle, half shaft, half axle sleeve pipe used in rear axle, the transmission gear in bridge box, etc., all of them are the key forgings for the safe operation of automobile.
2. Forging of diesel engine
Diesel engine is a kind of power machinery, it is often used as the engine.Taking large diesel engine as an example, more than ten kinds of forgings are used, such as cylinder head, spindle neck, crankshaft end flange output end shaft, connecting rod, piston rod, piston head, crossheave pin shaft, crankshaft transmission gear, gear ring, intermediate gear and dye pump body.
3. Marine forging
Marine forgings are divided into three categories: main engine forgings, shafting forgings and rudder forgings.Main engine forging is the same as diesel engine forging.Shafting forgings have thrust shaft, middle shaft and stern shaft, etc.Rudder forging with rudder stock, rudder post, rudder pin, etc.
4. Forging of weapon
Forging plays an important role in the weapon industry.By weight, 60% of the tank is forgings.The barrel, muzzle retainer and tail of the gun, ribbed barrel and three-edged bayonet of the infantry weapon, launcher and fixing seat of depth charge of rocket and submarine, stainless steel body for high pressure cooler of nuclear submarine, shell and bullet are all forging and pressing products.Weapons are made of materials other than steel forgings.
5. Petrochemical forging
Forgings are widely used in petrochemical equipment.For example, manholes and flanges of spherical storage tanks, various tube plates required for heat exchangers, welded flanges for catalytic cracking reactors (pressure vessels), tube joints used in hydrogenation reactors, and cover, bottom cover and sealing head required for chemical fertilizer equipment are all forgings.