With the development of the global economy, wind energy has developed rapidly as a clean renewable energy source. As a major component of wind power generation, wind power bearings are in very harsh working conditions, high maintenance costs, and need to withstand changes in temperature, humidity and load and the scope is large.In order to make it work for a long time, heat treatment process is often used to improve the performance requirements of wind power bearings. The heat-treated wind power bearing has high hardness and often uses grinding as the final processing step.

With the increasing competition in the market of bearings, the turning instead of grinding process has become the development trend of the wind power bearing industry. Its high efficiency and low cost are not compatible with the traditional grinding process，but at the same time the toughness and wear resistance of the turning tool. Sexual requirements are high.

For high-hardness wind power bearings after heat treatment, cutting tools must meet the following performance requirements: 

(1)The cutting tool has high hardness, good wear resistance and high temperature resistance;

(2) has sufficient flexural strength and impact toughness;

(3) has good processing stability and oxidation resistance;

In this regard, Halnn developed three materials CBN tools, namely BN-H11, BN-S200 and BN-S20. Among them, BN-H11 grade CBN tool belongs to the brazed CBN tool, which is mainly used for continuous cutting conditions, with balanced wear resistance and fracture resistance, and is suitable for high-speed finishing. At high speeds, the tool life is 5-6 times that of ceramic inserts. BN-S200 grade CBN tool is a solid CBN tool with excellent wear resistance. It is mainly used for semi-finishing and finishing of bearings to ensure high surface finish. BN-S20 grade also belongs to the solid CBN tool, which not only can remove the bearing deformation amount, but also can withstand strong interrupted cutting conditions. It has high hardness, excellent thermal shock resistance and wear resistance, and its tool life is N times the ceramic tool. Cutting parameters are as follows:

Bearing

(Hardness: ≥HRC45)

The following is a brief introduction to Halnn CBN tools machining bearings.

(1) Finishing slewing bearing raceway, end face, hardness HRC47-55, margin <2mm: choose Halnn solid CBN tools BN-S200 grade (round tool), cutting parameters: 

Cutting depth(ap) ≤ 1 mm, 

Feed rate(Fr) = 0.05 - 0.35 mm / r, 

Cutting speed(Vc) = 60 - 250 m / min. 

Machining effect: The tool life is 7 times that of the ceramic tool, and the surface roughness is controlled between Ra 0.6-1.0.

(2) Finishing wheel slewing bearing outer circle, end face, hardness HRC47-55, channel hardness HRC55-62; margin ≥ 2mm: 

choose Halnn solid CBN toolsBN-S20 grade, cutting parameters: 

Cutting depth(ap)= 1 mm, 

Cutting speed(Vc)= 140 - 180 m / min. 

Machining effect: The tool has a long service life and can replace rough grinding, and the surface roughness reaches Ra0.4.

(3) finish turning metallurgical bearing outer circle, inner hole, hardness HRC62: choose Halnn brazed CBN tool BN-H11 grade, 

cutting parameters: 

Cutting depth(ap)≤ 1mm, 

Feed rate(Fr)= 0.05-0.35mm / r, 

Cutting speed(Vc)= 60-250 m/min. 

Machining effect: Compared with other CBN tools, it has a long service life and the surface roughness is within Ra0.8