The difference between forgings and castings

Metal can improve its microstructure and mechanical properties after forging processing. After hot working and deformation by forging method, the casting structure transforms from coarse dendrites and columnar grains to equiaxed recrystallized structures with finer and uniform sizes due to the deformation and recrystallization of the metal. This causes the original segregation, porosity, porosity, slag inclusion, and other compaction and welding in the steel ingot, making the structure more compact and improving the 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, forging processing can ensure the continuity of the metal fiber structure, keeping the fiber structure of the forging consistent with the shape of the forging. The metal flow line is complete, which can ensure that the parts have good mechanical properties and long service life. Forgings produced by precision forging, cold extrusion, warm extrusion and other processes are incomparable to castings.

Aircraft forgings

By weight, about 85% of the components on an aircraft are forgings. The turbine discs, rear journals (hollow shafts), blades, wing beams of aircraft engines, rib plates of the fuselage, wheel supports, and inner and outer cylinders of landing gears are all important forgings related to aircraft safety. Aircraft forgings are often made of valuable materials such as high-strength, wear-resistant, and corrosion-resistant aluminum alloys, titanium alloys, and nickel based alloys. In order to save materials and energy, most aircraft forgings are produced using die forging or multi-directional die forging presses.

Automotive forging

By weight, there are 17% -19% of forgings on cars. A typical car is composed of 15 components, including the body, trunk, engine, front axle, rear axle, frame, gearbox, transmission shaft, steering system, etc. The characteristics of automotive forgings are complex appearance, light weight, poor working conditions, and high safety requirements. The crankshafts, connecting rods, camshafts, front beams, steering knuckles required for the front axle, half shafts, half shaft sleeves used for the rear axle, and transmission gears inside the axle box used in automotive engines are all key forgings related to the safe operation of automobiles.

Diesel engine forgings

A diesel engine is a type of power machinery that is commonly used as an engine. Taking a large diesel engine as an example, more than ten types of forgings are used, including cylinder head, main journal, crankshaft end flange output shaft, connecting rod, piston rod, piston head, crosshead pin shaft, crankshaft transmission gear, ring gear, intermediate gear, and dye pump body.

Marine forgings

Marine forgings are divided into three categories: main engine forgings, shaft forgings, and rudder forgings. The main engine forging is the same as the diesel engine forging. Shafting forgings include thrust shafts, intermediate shafts, and stern shafts. Rudder forgings include rudder stock, rudder pillar, rudder pin, etc.

Petrochemical forgings

Forgings have a wide range of applications in petrochemical equipment. The manholes and flanges of spherical storage tanks, various tube plates required for heat exchangers, integral forged cylinder bodies (pressure vessels) of welded flanges for catalytic cracking reactors, cylinder sections used for hydrogenation reactors, and top, bottom, and head covers required for fertilizer equipment are all forgings.

Mining forgings

Calculated by equipment weight, the proportion of forgings in mining equipment is 12-24%. Mining equipment includes: mining equipment, hoisting equipment, crushing equipment, grinding equipment, washing equipment, sintering equipment.

Thermal power forgings

There are four key forgings in thermal power generation equipment, namely the rotor and retaining ring of the steam turbine generator, as well as the impeller and rotor of the steam turbine.

Hydroelectric forgings

The important forgings in hydroelectric power station equipment include the main shaft of the water turbine, the main shaft of the water turbine generator, the mirror plate, and the thrust head.