The reason for the existence of the main bearing ring fracture
March 31, 2014 8:19pm CST
A, raw materials, Raw materials mixing, osteoporosis, brittle element segregation or carbide liquid chromatography, mesh, ribbon, not survived well and other defects in processing work together is not eliminated or improved, can cause stress concentration and weaken the ferrule basic strength, become the source of crack. Preventive measures is insisted on a supply of main channel, and try to purchase stable and reliable quality of steel, to strengthen the incoming inspection of purchased steel, from the source the better off. Second, the production and equipment 1. Forging, forging process, if produce burnt, overheating, such as inside crack reticulate carbide decreases the toughness and strength of the ring. So must always be strictly control the processing temperature, cyclic heating and cooling conditions, such as spray cooling after forging, etc., especially in large breed ring after finish forging, the temperature is above 700 ?, the shall not be piled up to put. 2. Heat treatment: heat treatment equipment is closely monitoring workshop is an important work. The reliability of the monitoring equipment. Records of monitoring data. Quenching cooling conditions. Tempering process strictly. 3. Monitoring of grinding process. Products bearing ring grinding burn and grinding cracks are not allowed to exist, especially the inner ring to taper of the mating surfaces shall not be burned. If ring should be full inspection after pickling, picking burns products, severe burns can't repair or repair the unqualified should be scrapped, grinding burn is not permitted in the ring into the assembly process. 4. Identity management, steel storage to the front of the ferrule grinding, after each working procedure must be strictly management, strictly distinguish GCr15 and GCr15SiMn two kind of material made of different materials and products. Three, ring throwing, overload and the possibility of fracture and fatigue fracture, especially poor service condition of bearing (e.g., 22328, etc.). Study of ring fracture phenomenon, not only from the material and production process of the defects of the Angle to think, but also the structure of bearing parts size, processing and measuring method, processing technology, through analyzing factors such as bearing service conditions. 1. The bearing structure and service conditions. 2. Strengthen the technology research, improve the processing technology, improve the quality of processing, reduce the potential for defects of machining. 3. The improved process monitoring method, and to promote the quality improvement of processing.