Tag Archives: abec bearings

High quality IKO bearing of material for smelting
Rolling bearing quality level with IKO bearing steel quality are having close connection. Due to bearing steel has the characteristics of smelting quality, than the general industrial steel are much stricter, such as steel, chemical composition, purity, organization and structure uniformity.
First, the strict requirements for chemical components
General IKO bearing steel is of high carbon chromium bearing steel, the carbon content of around 1%, add about 1.5% chromium, manganese, silicon and small amounts of elements of hypereutectoid steel. Chromium can improve the properties of heat treatment, increasing the hardenability, microstructure uniformity, tempering stability, but also can improve the steel rust resistance and grinding performance. When the Cr content exceeded 1.65%, will increase steel after quenching residual austenite, reducing the hardness and dimensional stability, increased carbide inhomogeneity, reduce the impact toughness and fatigue strength. Therefore, high carbon chromium bearing steel with the volume control is in 1.65% the following. Only strict control in bearing steel chemical composition content, it may pass through the heat treatment processes to meet IKO bearing properties of the microstructure and hardness of.
Second, strict high precision size requirements
Rolling IKO bearing steel size requirements of higher precision, this is because most of the IKO pressure bearing parts have been formed. In order to save raw materials and improve labor productivity, most of IKO bearing rings are forging, cold heading or ball is rolled through molding, the small size of the roller is after cold forging. If the dimensional accuracy of steel is not high, you can not accurately calculate the size and weight, thus IKO is no guarantee that the quality of products bearing parts, but also easily lead to manufacturing equipment damage.
Third, particularly stringent cleanliness requirements
Steel is a steel purity impurity in the number, the higher the purity, steel non metallic inclusions in less. Bearing steel in the oxides, silicates and other harmful impurity content and IKO bearing early fatigue peeling, IKO bearing life reduce has the very big relations. Especially fragile impurities harmful, because in the process of easily from the metal substrate is peeled down, seriously affect the IKO bearing after finishing the appearance quality. Therefore, in order to improve the IKO bearing service life and reliability of IKO, must reduce impurity content in bearing steel.
Fourth, strict macrostructure and microstructure ( high times ) organizational requirements
Bearing steel macrostructure refers generally to osteoporosis, center porosity and shallow analysis, microscopic ( high times ) tissues including steel annealing microstructure, carbide reticulated, ribbon and solution of. Carbide eliquation is hard and brittle, harmfulness and the brittle inclusion of same. Reticular carbide lowers the impact toughness of the steel, and the organization is not uniform, easy deformation and cracking of quenching. The banded Carbide Annealing and quenching and tempering effect of organization and contact fatigue strength. Low, high times organization the quality of rolling bearing IKO quality have great influence, therefore, IKO bearing manufacturing specification of low, high times organization has strict requirements.
In fifth, the external and internal defects particularly stringent requirements
On IKO bearing steel, external defects including cracks, slag, burr, scarring, oxide, internal defects including shrinkage, bubble, white spots, severe osteoporosis and segregation. These defects for IKO, IKO bearing processing bearing performance and service life has a great influence, IKO bearing data specification clear regulations do not permit the emergence of these defects.
Sixth, particularly strict requirements of carbides
Bearing steel, if there is serious non homogeneous distribution of the carbide, the heat treatment process is easy to cause the uneven microstructure and hardness, microstructure inhomogeneity on contact fatigue intensity has a great influence. In addition, serious carbide inhomogeneity is also easy to make the IKO bearing parts in the quenching cooling crack, carbide inhomogeneity can lead to IKO bearing life is reduced accordingly, IKO bearing data specification, the different specifications of steel have a clear special requirements.
Seventh, particularly stringent requirements in appearance of decarburized layer
IKO bearing materials specification for steel surface decarbonization layer has strict rules, if the surface decarbonization layer does not meet the standards specified range, and prior to heat treatment process and not all of the removed, is in heat treatment quenching process is prone to quenching crack, causing parts of the scrap.
Eighth, other requirements
Bearing steel material specifications also on bearing steel smelting method, oxygen content, hardness, fracture, the remaining elements of annealing, spark test, condition of delivery, mark has strict requirements.