Metal can improve its structure and mechanical properties after forging. After the casting structure is deformed by the forging method due to the deformation and recrystallization of the metal, the original coarse dendrites and columnar grains become the equiaxed recrystallized structure with finer grains and uniform size, which makes the original segregation in the steel ingot, The compaction, and welding of looseness, pores, slag inclusions, etc. make the structure more compact and improve the plasticity and mechanical properties of the metal.
Generally speaking, the mechanical properties of castings are lower than the mechanical properties of forgings of the same material. In addition, the forging process can ensure the continuity of the metal fiber structure, keep the fiber structure of the forging consistent with the shape of the forging, and the metal streamline is complete, which can ensure that the parts have good mechanical properties and long service life. Precision die forging and cold extrusion are used. Forgings produced by processes such as warm extrusion, etc. are unmatched by castings.
Diesel engine forgings
The diesel engine is a kind of power machinery, it is often used as the engine. Taking a large diesel engine as an example, the forgings used include cylinder head, main journal, crankshaft end flange, output end shaft, connecting rod, piston rod, piston head, crosshead pin shaft, crankshaft transmission gear, ring gear, intermediate gear, and oil dye pump More than ten kinds of body and so on.
Marine forgings
Marine forgings are divided into three categories, main engine forgings, shafting forgings, and rudder forgings. The main engine forgings are the same as the diesel engine forgings. Shafting forgings include thrust shafts, intermediate shafts, and stern shafts.
Petrochemical forgings
Forgings are widely used in petrochemical equipment. Such as manholes and flanges of spherical storage tanks, various tube plates required for heat exchangers, butt-welded flanges for the whole forged cylinder (pressure vessel) of catalytic cracking reactors, cylinder sections used in hydrogenation reactors, and fertilizers The top cover, bottom cover, head, etc. required by the equipment are all forgings.
Mine 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.
Nuclear power forgings
Nuclear power is divided into two types: pressurized water reactor and boiling water reactor. The main large forgings of nuclear power plants can be divided into two categories: pressure shell and reactor internals.
The pressure shell includes cylinder flange, nozzle section, nozzle, upper cylinder, lower cylinder, cylinder transition section, bolts, etc.