Halnn Tools CBN Inserts processing bearing steel Solutions
Bearing steel is the steel used to make balls, rollers, and bearing rings. Bearing steel has high hardness and wear resistance, as well as high elastic limit. Because the uniformity of the chemical composition of the bearing steel and the distribution of carbides are very strict, it is one of the most demanding steel grades among all steels. one. It is widely used in transportation, wind power energy, mining machinery, power equipment and other fields.
In order to meet the performance requirements of bearing steel, general bearing steel needs to have the following conditions: 1) good fatigue strength; 2) high hardness or hardness that can meet the bearing performance requirements; 3) wear resistance and low friction coefficient; 4) Elastic limit; 5) Good impact fracture toughness; 6) Good dimensional stability; 7) Good rust resistance; 8) Good cold and hot workability. ...
After the bearing steel is cast, the hardness requirements of the workpiece are different according to the performance of different workpieces. Therefore, the bearing steel needs to undergo a heat treatment process during the processing to meet the performance requirements of the bearing.
The simple processing technology of bearing steel is smelting-casting-annealing-rough machining-quenching, tempering-finishing. The hardness of the workpiece after quenching and tempering is generally above HRC45. For high-hardness bearing steel parts, traditional tools (carbide tools and ceramic tools) can no longer meet the processing requirements. The performance of cemented carbide tools will not be repeated here. At present, the tool materials suitable for processing high hardness bearing steel parts include ceramic tools and CBN inserts. Continue cutting. For example, the deformation of the workpiece after heat treatment is small, the surface is relatively flat, and the ceramic tool is suitable when the margin is small.
The shortcomings of CBN inserts are as brittle as ceramic tools, but compared to ceramic tools, CBN inserts still have a certain impact resistance, and their high hardness, high strength, and good wear resistance make them suitable for processing. The main tool material for high hardness bearing steel. In particular, the non-metallic binder CBN tool developed by Halnn Tools breaks the claim that CBN inserts can only process workpieces at a small feed rate and cannot cut intermittently.
Halnn Tools has developed CBN inserts BN-S20, BN-H11 and BN-S20 for bearing steel, making it easy to process high-hardness bearing steel parts. The BN-S200 and BN-S20 grades belong to solid CBN inserts (the tool pictures are the same), and the BN-H11 grades belong to CBN inserts during welding.
Halnn Tools selects relatively suitable tool grades and cutting parameters for different workpieces, hardness, and margin. The plan is as follows:
(1) Finish turning bearing raceway, end face, hardness HRC47-55, margin <2mm: choose Halnn Tools CBN insert BN-S200 brand (round insert), cutting parameters: ap ≤1mm, Fr=0.05-0.35mm/r, Vc=60-250m/min. Processing effect: The tool life is 7 times that of ceramic tools, and the surface roughness is controlled between Ra0.6-1.0.
(2) Finish turning slewing ring bearing outer circle, end face, hardness HRC47-55, channel hardness HRC55-62; margin ≥ 2mm: choose Halnn Tools CBN insert BN-S20 grade, cutting parameters : Ap=1mm, Vc=140-180m/min. Processing effect: long tool life, can replace rough grinding, surface roughness reaches Ra0.4.
(3) Finish turning metallurgical bearing outer circle and inner hole, hardness HRC62: choose Halnn Tools non-metal adhesive CBN insert BN-H11 grade, cutting parameters: ap≤1mm, Fr=0.05-0.35mm/r, Vc=60-250m/min. Processing effect: Compared with foreign PCBN inserts, the service life is longer, and the surface roughness is within Ra0.8.
(4) The inner and outer rings of small and medium-sized bearings and non-standard bearings for fine turning, (Gcr15 material hardness above HRC62), choose Halnn Tools BN-H20 brand (margin <0.5mm) and BN-S20 brand (margin> 1mm), and Cutting parameters: ap=0.1-0.3mm, Fr=0.1-0.12mm/r, Vc=120-180m/min. Processing effect: BN-S20 brand processing hardened bearing steel parts with a diameter of 500mm or less can complete the rough grinding process in one pass.