please contact sales@tanchin.hk for any inquiry
The quality of rolling bearings is very close to the quality of IKO bearing steel. Due to the characteristics of bearing steel, the quality of smelting requirements than the general industrial steel to be much more stringent, such as steel chemical composition, purity, organization and structural uniformity.
First, strict chemical composition requirements
General IKO bearing steel is mainly high-carbon chromium bearing steel, that is about 1% carbon content, adding about 1.5% of chromium, and contains a small amount of manganese, silicon element over eutectoid steel. Chromium can improve the heat treatment performance, improve the hardenability, uniformity of the organization, tempering stability, but also can improve the anti-rust properties of steel and grinding performance. However, when the chromium content exceeds 1.65%, quenching will increase the retained austenite in steel, reduce the hardness and dimensional stability, increase the carbide heterogeneity, reduce the impact toughness and fatigue strength of steel. To this end, high-carbon chromium bearing steel in the chromium content is generally controlled at 1.65% or less. Only by strictly controlling the chemical composition of the bearing steel content, can be achieved through the heat treatment process to meet the IKO bearing performance of the organization and hardness.
Second, strict high-precision size requirements
Rolling IKO bearings require high dimensional accuracy, which is because most IKO bearing parts have to be pressure molded. In order to save raw materials and improve labor productivity, the vast majority of IKO bearing rings are forging molding, steel ball is cold heading or hot rolling molding, small size of the roller is also cold heading forming. If the steel size accuracy is not high, it can not accurately calculate the size and weight of the material, which can not guarantee IKO bearing parts of the product quality, but also likely to cause damage to manufacturing equipment.
Third, especially the strict purity requirements
The purity of steel refers to the amount of impurities contained in steel, the higher the purity of steel, the less the non-metallic inclusions. Bearing steel in the oxide, silicate and other harmful impurities and IKO bearings early fatigue peeling, IKO bearing life has a great relationship. Especially the most harmful brittle impurities, due to the processing process easily from the metal matrix peeling off, seriously affect the IKO bearings after finishing the appearance of quality. Therefore, in order to improve the life of IKO bearings and reliability, it is necessary to reduce the impurity content of IKO bearing steel.
Fourth, strict low magnification organization and micro (high power) tissue requirements
Low magnification of bearing steel refers to the general loose, central loose and flat, micro (high power) organizations, including steel annealing organization, carbide mesh, ribbon and liquid chromatography. Carbide liquid hard and brittle, harmful and brittle inclusions the same. Mesh carbide reduces the impact toughness of steel, and the organization is not uniform, easy to deformation and cracking when quenching. The banded carbides affect the annealing and quenching tempering tissues as well as the contact fatigue strength. The advantages and disadvantages of the low and high power organizations have a great influence on the quality of the rolling IKO bearings. Therefore, the IKO bearing manufacturing specification has strict requirements for low and high power organizations.
Fifth, external defects and internal defects are particularly stringent requirements
For IKO bearing steel, external defects include cracks, slag, burrs, scarring, scale, etc., internal defects include shrinkage, bubbles, white spots, severe loose and segregation. These defects for IKO bearing processing, IKO bearing performance and life have a great impact, IKO bearing data specification clearly does not allow these defects.
Sixth, particularly stringent requirements for carbide nonuniformity
Bearing steel, if there is a serious distribution of carbides uneven, in the heat treatment process is likely to cause uneven organization and hardness, steel nonuniformity of the contact fatigue strength have a greater impact. In addition, the serious carbide non-uniformity is also easy to make IKO bearing parts in the quenching and cooling cracks, carbide unevenness will lead to IKO bearing life reduction Therefore, IKO bearing data specifications, the different specifications of the steel are Clear special requirements.
Seventh, particularly stringent appearance decarburization requirements
IKO bearing data specifications on the steel surface decarburization layer has a strict requirement, if the appearance of decarburized layer does not meet the requirements of the standard range, and in the heat treatment before the process did not remove all of them, in the heat treatment quenching process It is prone to quenching cracks, resulting in scrap parts.
Eighth, other requirements
Bearing steel material specifications also on the bearing steel smelting methods, oxygen content, annealing hardness, fracture, the remaining elements, spark inspection, delivery status, logo, etc. have strict requirements.


please contact sales@tanchin.hk for any inquiry
PREVIOUS:Bearing side cover packing Improvement        

F682X F692X F602 F694Z F695Z F696Z F697Z F698Z F699Z F604Z F605Z F606Z F607Z F608Z F624Z 6032DU 6030V 625VV 6032DDU 626DD