High carbon chromium bearing steel (GCr15) since 1905 by Germany for rolling bearing manufacturing after only 15years, it is widely used in bearing industry all over the world, so far has been the world bearing industry mainbearings were the largest steel. Metallurgical quality has made considerable progress in the past 30 years, mainly in the development of refining, vacuum degassing technology, so that the degree of purity greatly improve the bearingsteel, bearing life has significant growth.

1 vacuum degassing of steel

Vacuum degassing technology for bearing steel began to be used in twentieth Century six, seventy time. The furnace vacuum processing technology, there are several common methods: vacuum degassing method (RH method), vacuum lifting degassing method (DH method), ASEA-SKF ladle refining method, vacuum arc furnace andvacuum processing method (VAD method) and SKF-MR method.

2 electroslag steel and double vacuum steel

Rolling bearing high reliability requirements, such as aero generator, high speed trains and other important rolling bearing, usually by electroslag steel or double vacuum steel.

(1) the electroslag steel (ESR) by electroslag remelting method (ESR) bearing steel production are referred to aselectro slag steel. It is composed of electric furnace steel bearing (or degassed bearing steel) to prepare steel bar as electrode, in particular slag washing pool to arc melting refining, and re zoned crystals into ingots, is characterized by further reducing the inclusion content, eliminate the coarse inclusions and greatly improve thedistribution of inclusions. Steel with high density, microstructure uniformity.

(2) double vacuum steel (VIM+VAR) by vacuum induction furnace (VIM) will concentrate smelting bearing steel andcast bearing steel rods as cathode, followed by vacuum consumable furnace to the electrode to arc melting, meltingand re crystallization region into ingots, the so-called consumable vacuum arc remelting (VAR) method. Bearing steelproduced by this method is commonly known as the double vacuum steel. The characteristics of high degree ofpurity, segregation is very small, dense uniform. Necessary is also can use multiple vacuum consumable smeltingproduction of ultra pure bearing steel.