Babbitt: the use and production of
Babbitt is an alloy based on lead or tin. Its difference — high anti-friction characteristics. His name was in honor of Babbitt Babbitt American Isaac. It was he who in 1839 invented a new alloy. When developing copper as additives may be used, sodium, nickel, magnesium, antimony, arsenic, tellurium. Babbitt structure is heterogeneous. It consists of a soft — tin or lead — bases with solid inclusions. Special features babbitt:
-Small Friction coefficient;
-Small Melting temperature reaching 300−440oS;
-Good Resistance to wear by friction;
-Good Running-in ability.
There are three types of babbitt. Lead brands BN, BK2, BKA, SAE13−14−15, BK2SH, ASTM15, ASTM7. Tin marks B83, B83S, B88, ASTM2, SAE12, SAE11. Lead-tin grades BS6, B16. Babbit used as an additional layer. It is poured or sprayed produce shell-bearing body. Next, the break-in period. After it finds the liner surface microrelief. For his account provided retention of lubricants between shaft and insert patches. Tin babbitt wins the lead in the field of corrosion resistance and wear resistance, thermal conductivity. Lead babbits have a higher operating temperature.
In the production of the starting materials in babbitt — tin and lead. Applying can be both primary and secondary metals. When making guided by GOST 1320−74. In accordance with babbitt it melted in the form of ingots. The weight of each is 22kg. On the surface of slag contamination is excluded. The break of the alloy should exhibit uniformity without oxides and slag. Babbits may be low alloyed and high. Here a crucial role is played by the additive.
Babbit BK2SH brand is characterized by low resistance to vibration, impact and heavy loads. Operating temperature is high enough. B83 alloy is used for bearings and components operating at high speeds and medium loads. This turbine, compressors, steam engines. Babbit brand BK2 is used in the manufacture of main and connecting rod bearings. Fusion BN poured bearings operating at moderate loads and speeds. It may be rolling mills, gearboxes, electric, steam turbines, and more. Babbit BCA mark is used in the production of axle friction bearings. They are installed on the rail transport units. Brand B16 is engaged in the bearings of generators, ball and tube mills, compressors, and other ships.