Only 15 years is the world bearing industry widely adopted ,high carbon chromium import bearing steel (GCr15) since 1905 by Germany for rolling bearing manufacturing, eliminate the bulky inclusion and greatly improve the distribution of the inclusions. So far has been the world bearing industry of the most main bearing steel. The metallurgical quality in nearly 30 years has made good progress, the characteristic is further reducing the inclusion content, mainly displays in concise technology, vacuum deairing with the development of technology, make bearing steel of pure degree greatly raised, bearing life also have significant growth.

1. The vacuum takes off the gas steel

Common outside the furnace vacuum processing technology has the following kinds of methods: NSK bearing vacuum circulation degassing method (RH method), bearing steel vacuum deairing with the technology used in 20 century began six, in the seventy s. Vacuum ascension to take off the gas method (DH method), ASEA-SKF ladle heating furnace, vacuum arc chastening method the vacuum treatment method (VAD method) and SKF-MR method.

2. The steel slag and double vacuum steel

High reliability requirements of rolling bearing, such as air generator and high-speed train, and other important roll bearing FAG, usually by electric steel slag or double vacuum steel.

(1) features is pure degree is extremely high, segregation is small, compact structure even. The steel slag (ESR) by the slag remelting method (ESR) the bearing steel slag as electrical steel. It is by the electric furnace bearing steel (or to take off the gas bearing steel) to expect too much frequently great as electrode preparation, in special slag washing pool again within arcs melting point to points and regional crystallization spindles into, steel send density high, the organization is more homogeneous.

(2) the method of the production of the bearing steel commonly known as double vacuum steel. NTN bearing the double vacuum steel (VIM + VAR) with vacuum induction furnace (VIM) will concentrate of bearing steel smelting and the molten image bearing steel bar as electrode cathode, and then in a vacuum furnace from consumption the ignition electrode to melt, realize the regional smelting and to recrystallize into ingots, called the power vacuum arc remelting (VAR) method. Necessary is also can use many times since smelting production consumption vacuum super pure bearing steel.
 



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