FANADE Industry Co.- professional supplier of Fag 6203 bearing.FANADE Bearing product type involves Deep Groove Ball Bearings,Taper Roller Bearing,Spherical Roller Bearings,Needle Roller Bearing,Angular Contact Ball Bearings,Cylindrical Roller Bearing,Thrust Roller Bearings,we provide all kinds of high quality imported bearing,such as skf,fag,nsk,timken,ina,ntn and so on.Today we talk about Four common failures of FAG 6203 bearing.Many ways of failure of imported 6203 bearings are known to us.It happens to many FAG imported 6203 bearing users that examination has to be done to see if there is any failure after the 6203 bearing is working for a while.Common causes for failure include the following.6203 bearing these in mind,we will know what we will do in inspection.
According to the formation principle of the grinding metamorphic layer of working surface of FAG imported 6203 bearings,the main factors affecting the metamorphic layer are grinding heat and grinding force.The following are analysis of the reasons for the failure of FAG 6203 bearings.
1.Grinding heat of FAG imported 6203 bearings
When FAG 6203 bearings are in the process of grinding,the grinding wheel and workpiece contact area consumes large amounts of energy,produce a lot of grinding heat,causing the local instantaneous grinding zone temperature.linear motion heat transfer theory derive a formula to calculate the instantaneous method or application of infrared temperature measurement thermocouple method and experimental conditions can be found in the instantaneous temperature in the grinding zone 0.1 ~ 0.001ms up to 1000 ~ 1500 ¡Ã¦.Such instantaneous heat,enough to make the work surface to produce a certain depth of the surface layer of high-temperature oxidation,amorphous organization,tempering secondary hardening,cracking or burn a variety of changes.
( 1 ) the surface oxide layer
Steel surface reacts with oxygen in the air under a instantaneously high temperature,and create a very thin (20 ~ 30nm) iron oxide layer.It is noteworthy that the oxide layer thickness and the total thickness of the deteriorating surface layer tested to be in corresponding relationship.This shows that the thickness of the oxide layer is directly related to the grinding process,and the grinding is an important indicator of quality.
( 2 ) amorphous tissue layer
Instantaneous temperature in the grinding zone makes the surface reach a molten state,the molecular flow of molten metal in turn has been uniformly applied to the working surface,the base metal was cooled at a rate fast to form a thin layer of amorphous tissue layer.It has high hardness and toughness,but it’s only about 10nm,can easily be removed in precision grinding.
( 3 ) high-temperature tempering layer
Instantaneous grinding zone temperature enables a certain depth (10 ~ 100nm) in the workpiece is heated above the tempering heating temperature.In case austenitizing temperature does not reach,with the heating temperature is increased,the surface temperature of the heating layer by layer to produce corresponding retempered tissue changes or tempering,the hardness is decreased.The higher the heating temperature,hardness decreased but also more powerful.
( 4 )Second quenching layer
The instantaneous high temperature in the grinding zone will make the surface layer heated to the austenitizing temperature (Ac1) above,the layer of tissue in the subsequent austenite during cooling,and was again quenched to martensite.Those who have secondary quenching workpiece burns,under its secondary hardening layer must be low hardness tempering layers.
( 5 ) grinding cracks
Burns during the second quenching will change the stress of the surface layer of pieces.With second quenching zone in a pressed state,following tempering the material is present in the greatest area of tensile stress,this is most likely to occur where the core cracks.Crack easily along the austenite grain boundaries of the original transmission.Serious burns can cause the entire ground surface cracks ( mostly crack ) cause the workpiece scrap.
2.Metamorphic layer formed by the grinding force
In the grinding process,the surface layer of the grinding wheel will be the cutting force,the force of the compression and friction.Especially the role of the two,so that the surface layer of the plastic layer a strong directivity and the hardening layer.These changes will inevitably affect the metamorphic layer surface layer of residual stress.
( 1 ) cold plastic deformation layer
In the grinding process,every particle is equivalent to an abrasive cutting edge.In many cases,however,the rake angle of the cutting edge is negative,in addition to the cutting action of abrasive grains,is exposed to the extruding surface of the workpiece ( plow effect ),so that the surface to leave a clear plastic layer.Such deformation of the deformable layer with the grinding wheel blunt the extent and amount of grinding feed increases.
( 2 ) plastic deformation ( or high temperature deformation ) layer
Instantaneous temperature at the working surface by the grinding heat can make the elastic limit of a certain depth of the surface layer sharply decreased,even to the extent of the disappearance of flexibility.In this case the working surface of the free layer in the grinding force,particularly compression force and the frictional force,caused by stretching of the metal substrate is restricted,the surface is compressed ( more plow ),resulting in a surface layer of plastic deformation.High-temperature plastic deformation in the grinding process remains unchanged,with the workpiece surface temperature increases.
( 3 ) hardening layer
Sometimes microhardness method and metallurgical method can help us spot the deformation of the surface layer caused by elevated hardness and processing.
In addition to grinding,casting and heat treatment of surface decarburization layer caused by heating,and then the subsequent processing if not completely place,also remaining on the surface cause surface softening of the deterioration of the 6203 bearings contribute to early failure of FAG.
3 Failure by fracture
FAG 6203 bearing Failure was mainly due to two factors defects and overload.When the applied load exceeds the ultimate strength of the material and cause parts breakage called overload fracture.The main reason is the host overloads sudden failure or improper installation.FAG 6203 bearings parts of micro-cracks,shrinkage,bubbles,and chunks of foreign matter,organizations and local overheating can cause burns and other defects in the defect at the time of fracture impact overload or excessive vibration,called the defect fracture.It should be noted that FAG 6203 bearings in the manufacturing process,the raw materials into the plant reinspection,forging and heat treatment,quality control,process control,instrumentation correct analysis by the existence of the defect,the future still need to strengthen controls.But in general,often FAG 6203 bearing Failure by fracture are mostly due to overload.
4 Failure by clearance changes
FAG 6203 bearings at work,due to external influence or internal factors,with the gap so that the original change,reduced accuracy,and even lead to ” bite ” is called clearance changes fail.External factors such as excessive interference,the installation is not in place,the amount of expansion caused by temperature,instantaneous overload,internal factors such as residual stress and retained austenite is unstable and so is the main cause of failure of the clearance change.
Contact
International Call: 00852-3071788
Website: www.fagbearings-hk.com