GB/T 1174-92 Cast bearing alloys
Cast bearing alloys are metallic materials designed for use in the manufacture of bearing components like shafts, bushings and wheels. These alloys must have good wear and corrosion resistance, strength and hardness, in addition to other properties depending on the application.
The Chinese National Standard GB/T 1174-92 defines the requirements for cast bearing alloys. The scope of application of the standard is to define the chemical composition, mechanical properties, and metallurgical quality requirements for cast bearing alloys used for making metal products for the engines, airframes and other aviation, shipbuilding, power plants, and industrial engineering usages. According to its classification, this standard applies to seven bronzes, two aluminum alloys, lead-based alloys, manganese steel alloys, and iron-based alloys.
The seven bronze alloys are composed of copper, tin, zinc, and manganese. The bronze alloys are known for their exceptional wear resistance and good strength, hardness, and ductility. They are used for making bearing components like bushings, shafts, and wheels.
The two aluminum alloys are composed of aluminum, copper, magnesium, and manganese. They provide good dimensional stability, excellent load-bearing properties, and an overall low weight. Due to their exceptional corrosion resistance, these alloys are primarily used for making bearings for the aviation industry.
The lead-based alloys are composed of lead, tin, sulfur, and antimony. These alloys provide good wear resistance and low friction coefficient, in addition to shock and vibration absorption. Due to their low thermal expansion coefficient, high melting point, and excellent machinability, these alloys are used in applications relying on self-lubrication and high-temperature operation.
The manganese steel alloys are composed of manganese, silicon, carbon, phosphorus, and sulphur. These alloys are very difficult to machine, but are very hard and tough, providing exceptional wear and impact resistance. These alloys are used in high-wear applications like rock crushers, heavy-duty gears, and excavator teeth.
Finally, the iron-based alloys are different combinations of iron, chromium, silicon, cobalt and various other elements. These alloys provide high tensile strength, good wear and heat resistance, and good corrosion resistance. Iron-based alloys are used in applications that need to withstand extreme conditions and harsh environments.
The metallurgical requirements for all the alloys indicated in this national standard are for their physical and chemical characteristics, with regards to their size, surface finish, metallurgical analysis, and other quality criteria.
In conclusion, GB/T 1174-92 defines the requirements for cast bearing alloys, used for aviation, shipping, engineering and other applications, based on the particular alloys composition. The alloys must meet certain chemical, mechanical, and metallurgical requirements, in order to provide the best possible performance in their intended application.
