The performance of the rolling bearing steel should have

Modern machines require bearings in high load and high rotation speed, high rotating accuracy, working in a wide temperature range, high reliability. Therefore making choice when rolling bearing material is appropriate for its using performance has very big effect. And the basic requirements for materials is decided by bearing damage forms. Under normal circumstances, the rolling bearing is the main damage form under the action of alternating stress fatigue spalling, and because of the friction and wear, which makes people lose bearing accuracy. In addition, there is crack, indentation, corrosion, etc. Have higher contact fatigue strength of the rolling bearing during operation, the roller in rolling bearing between the inner and outer ring raceway, the contact part under periodical alternating load, the bulls can reach hundreds of thousands of times per minute, under the effect of repeated periodic alternating stress, the contact surface of metal fatigue spalling, caused the bearing vibration and noise increases, working temperature rise sharply, the damaged bearing, in the end, is called the contact fatigue damage. Contact fatigue damage is the main form of bearing normal damage. And the contact fatigue strength high means its anti-fatigue ability is strong, for rolling bearing steel, therefore, should be has high contact fatigue strength. Have good wear resistance of rolling bearing, in addition to outside the rolling friction, sliding friction occurred at the same time, the main part of the sliding friction is: between roller and race, rolling element and cage pocket between holes, the cage and ring lead guard as well as between roller end and ring lead guard and so on. Both macro and micro can bring contact surface wear of sliding friction, the existence of the sliding friction in the rolling bearing inevitably bearing wear parts. If the bearing steel wear resistance is poor, the rolling bearing will prematurely due to abrasion loss due to the rotation accuracy or precision bearing vibration increase, reduce the service life. Therefore, for bearing steel should have good wear resistance. Have higher elastic limit due to the contact area between roller and ring raceway is small, bearing under the load, especially in the large load, the contact surface contact pressure is very big. In order to prevent too large plastic deformation in high contact pressure, the bearing precision loss or surface cracks, bearing steel is therefore required has higher elastic limit. A suitable hardness hardness of contact fatigue strength, wear resistance, elastic limit, has direct influence relations, therefore, the hardness of rolling bearing has a direct impact on rolling bearing a variety of life. Rolling bearing steel hardness is not the higher the better, the size is appropriate, too big or too small will affect the contact fatigue strength, wear resistance, elastic limit, thus influence the service life of the bearing. Rolling bearing in the national standard requirements: when the bearing ring and roller made of GCr15 bearing steel, the hardness shall be the HRC61 ~ 65; Made, GCr15SiMn should HRC60 ~ 64, a large number of tests show that, within the scope of the hardness, the contact fatigue strength, wear resistance and elastic limit is high. Has a certain toughness material hardness embodies the resistance to impact load capacity, a lot of rolling bearing in use will absorb a certain amount of impact load, thus for bearing steel has a certain toughness, to ensure that the bearing is not due to the impact damage. Good dimensional stability of rolling bearing is precision mechanical parts, its precision is micron ( µ m） To the measure. In the long-term storage and use, caused by material internal organization change the dimension of parts, can make the bearing the loss of accuracy, therefore, to ensure the dimensional accuracy of bearing, bearing steel should possess good dimensional stability. Have the production process of the rust resistance of rolling bearing is various, production cycle is long, the storage of some finished goods still need a long time, as a result, the bearing are easily happened in the production process and finished product stored corrosion, especially in the moist air, so, for bearing steel rust resistance. Have good process performance of the rolling bearing in production, the parts should pass more than cold, hot working process. This requires bearing steel should have good process performance, such as cold and hot forming performance, cutting, grinding and heat treatment performance, etc. , to adapt to the mass production, high efficiency, low cost and high quality needs. In addition, for use under special working conditions of bearing, the steel must also put forward the corresponding special performance requirements, such as high temperature resistant, high performance, corrosion resistance and anti magnetic, etc.