At this stage, China's steel output has been continuously improved, and the production capacity has gradually increased. Accompanied by the substantial increase in steelmaking equipment, the frequency of use has become larger and stronger. Therefore, the equipment will have various problems in operation. In order to maintain the stability of the production capacity, it is particularly important for the maintenance and maintenance of the equipment. Rolling equipment is an important equipment in the steel industry, and the bearing bush is an important mechanical component of this equipment, which is a necessary factor for its safe and stable operation. For equipment related to the rolling mill industry, it has a higher load capacity, a lower operating rate and a higher impact load. Therefore, the bearings on the equipment in the rolling steel industry often check the components with the bearing bush in the inspection and maintenance process, and repair and solve the problems in combination with the above problems.
1. Defects and treatment methods in the inspection of bearing bush of rolling steel machinery
The bearing bush made of babbitt alloy is different from other materials, and has strong wear resistance and wearability and friction resistance. At room temperature, the strength is sufficient and the friction compliance is also ideal. At the same time, the processing technology of the bearing bush is fine, and has good thermal conductivity, and the coefficient of thermal expansion is not large, and has certain corrosion resistance. Through the analysis and research on the actual use of the bearing bush, it can be understood that the biggest problem in the use of the babbitt bearing bush is wear, and the cause of the accidental wear causes the bearing bush to break and burn. Therefore, we must pay attention to the maintenance work of the bearing bush and extend its service life. However, in the actual maintenance work, there are always defects, so it is very important to analyze the maintenance process in detail and propose feasible measures.
(1) Defects and prevention of casting process. After casting the bearing bush, casting defects will occur due to the weak adhesion of the Babbitt alloy anti-friction layer and the bearing bushing. The main reason is that the preparation is unreasonable. The overall cleaning of the bearing lining may also be due to the problem of uneven tinning, so it should be prepared in advance. At the same time, the bearings should be cleaned in depth and degreased using high-temperature alkaline water boiling. After drying, it is necessary to use a saturated solution of zinc chloride to scrub at a specific heat to facilitate the bearing liner to hang tin, but it is necessary to ensure the thickness of the tin, and to ensure uniformity.
(2) Surface defects and treatment of bearing alloys. For the inside of bearing alloys, problems such as slag inclusion, pores and shrinkage holes are easy to exist, so it will have certain influence on various factors such as alloy composition and casting temperature. Because the mold and process of the rolling mill bearing bush are very simple, but the temperature will play a decisive role in the casting quality, so the temperature and quality are proportional. Once the temperature is too high, the problem of porosity, shrinkage or shrinkage is likely to occur. Therefore, the temperature is properly controlled, and the temperature is appropriately adjusted based on the ideal filling ability.
(3) The bearing material of the bearing pad is worn or slipped. For the rolling machinery, its own load impact is high and the running speed is too low. Therefore, in the actual operation process, it is easy for the shaft and the bearing bush to be in an incompletely lubricated state. In addition, there is direct friction between the shaft and the bearing bush, and the scratch on the contact surface is rough. Under this condition, if it is in the state of pressure and plastic deformation, grain transfer will inevitably occur, and finally the base metal will adhere. . Under this condition, shearing will inevitably occur. However, the abrasive grains of the alloy material will also rotate in the opposite direction. If this is the case for a long time, the surface of the bearing pad will adhere to the abrasive layer of the alloy material, and then the structure of the bearing bush itself. The shape is severely damaged and there is a problem of uneven force. At the same time, the lubricating oil film will also have a certain influence, so that the bearing bush temperature is too high and is burnt. Therefore, we must ensure that the bearing bush is in a state of lubrication. If deformation is found, it is necessary to take timely measures to make up for it.
(4) The bearing scratching affects the lubricity treatment, because the dynamic pressure oil wedge caused by the bushing scraping is not ideal, and the lubricating oil film between the shaft and the bearing bush does not meet the requirements, it will be overheated when the bearing bush is running. Affected and worn, which in turn has a negative impact on the operation of the rolling mill. Therefore, the lubrication of the bearing bush is effectively controlled to ensure the normal operation of the bearing bush and prolong the actual service life. In order to ensure the correctness and rationality of the bearing scraping, it should be ensured that the bearing capacity of the bearing bush is uniform, and the bearing area should be moderate. Only when the wedge of the lubricating oil is ensured to be smooth, the quality of the oil film can be ensured.