By manual arc welding and overlaying the roller surface of double roll crusher, the service life is up to 10 months and the clinker crushing effect is 150000 tons. The key points of surfacing welding are as follows: (1) selection of welding rod: d-65, d-667 and 506 welding rod shall be selected. Before surfacing, the welding rod shall be dried according to the operation instructions of welding rod, and shall be put in the heat preservation box for standby. (the use of 506 grade welding material can cause severe spalling. (2) roll surface treatment: roll surface repair can be divided into two methods: local direct repair welding and overall repair welding after overall removal, which can also be said to be two processes.
  For uneven wear along the roll width direction, uneven wear of pattern and hard points and overall wear of roll surface, local repair method can be adopted for direct repair welding; after 5-6 times of direct repair welding, due to the repeated high extrusion stress of the matrix, the welding micro cracks continue to expand, and a certain thickness of fatigue layer will be generated on the surface of the grinding roller. At this time, if the wear-resistant repair electrode is used to repair directly Welding, easy to produce interlayer falling off, so it is necessary to thoroughly clean the surface fatigue layer of grinding roller before surfacing the wear-resistant layer. The repair of roller surface in Xiexing cement plant is welding after overall removal. The roundness error and the diameter error of the two rollers should not be too large, either direct repair welding or repair welding after overall cleaning, otherwise the horizontal vibration of the roller press and the uneven load of the two rollers will increase. The fatigue layer of roller surface can be cleaned by carbon arc air gouging. The fatigue layer of roller surface should be planed to expose the base metal layer.
  Before surfacing, the welding rod shall be dried according to the instructions for welding rod, and the welding parts shall be preheated and slowly cooled after welding. (3) choose DC welding machine with power above 10KVA or AC welder with power above 20KVA. The DC welding machine should be connected in reverse (electrode connected to positive electrode). During surfacing welding, the no-load voltage should be no less than 70V and the current should be about 200A. If the no-load voltage is lower than 70V, the current shall be increased, and the welding rod and base metal shall be fully fused. The ratio of weld bead width to height is 3:1. Only in this way can it be fused with the base metal firmly and form the required wear-resistant structure. (4) surfacing sequence and thickness: after the roller surface is preheated, 506 welding rod shall be used to weld 1-3 layers, and the roller shall be rounded. Then several layers of d-667 are uniformly overlaid to reach the required thickness. After the d-667 welding layer is overlaid, another layer of d-65 with a thickness of 3-5mm is overlaid; after the d-65 welding layer is overlaid, a layer of crisscross pattern is overlaid with d-65. (the roller surface wear must have two factors: the pressure required for crushing materials and the relative sliding. The pressure is determined by the nature of the material and is usually difficult to change. However, it is easier to reduce the relative sliding between the material and the roller surface in the extrusion process through the roller surface pattern form. Although the herringbone pattern used in the early stage in China can prevent the circular sliding of materials, it does not restrict the axial sliding of materials in the extrusion process, especially when the materials with small particles are extruded, the wear is more serious. Compared with this, the wear resistance of roller surface with crowning pattern and hard point in the middle is the best.) The side length of crisscross pattern is 4-5cm, the width of weld bead is about 1cm, and the height is about 4mm. The thickness of each wear-resistant layer should be uniform, so as to keep the extrusion roller round in use. (5) during surfacing welding, three shifts shall be arranged to keep the weldment at a higher temperature for a long time.