Cold-type casting welding method of roller necks

Abstract

The invention discloses a cold-type casting welding method of roller necks, comprising: a procedure of adjusting the verticality of a cold-type neutral roller and fixing by an oblique iron, a fill forging process, a baking process, a mould assembling process, a wash melting process and a pouring process, wherein, in the fill forging process, the periphery of the roller neck on the oblique iron is filled and forged by water glass self-hardening sand until the height approaches to the height of the cross section of the roller neck; 1-4 layers of prefabricated fireproofing tiles are tightly arranged on the surrounding of the excircle of the roller neck; the end-face external diameter of the fireproofing tile is larger than the internal diameter of an overflow box; the upper flat surface of the fireproofing tile is lower than the cross section of the roller head; in the baking procedure, the water glass self-hardening sand automatically hardens for over 2 hours, and then the roller head fracture surface is baked and preheated by coal fire for 24 hours; and after the baking process is finished, the mould assembling process, the wash melting process and the pouring process are carried out. By the method provided by the invention, the defect of the air vents of the cast soldering products can be avoided, the casting quality is ensured, and the repair time of the roller is greatly shortened.

Description

technical field [0001] The invention relates to a method for repairing a large roll, which belongs to the field of casting. Background technique [0002] The material of the roll neck is ductile iron, affected by the casting conditions during the manufacturing process of the roll, the roll neck of the roll is prone to defects such as poor penetration and internal looseness, and the roll neck of the roll is the most stressed part , these defects are not allowed. If only the roll neck portion of the roll has a defect during the casting process, the roll will be scrapped and a new roll will be produced again, which is too much waste. When such a problem occurs, the currently commonly used rescue method is to process and remove the defective parts of the roll neck, and then use the cold casting welding process for the roll neck to recast a new section of the roll neck. Make repairs. [0003] The current roll neck cold mold casting welding process includes steps such as vertic...

AI Technical Summary

Problems solved by technology

[0004] There are many problems as follows when adopting the current cold joint method to repair the roll: 1) Since the refractory cement has a large water content and is limited by the conditions of the tooling, the surface of the refractory cement can only be baked, and the penetration depth is not enough. The drying effect is difficult to guarantee. After casting, the water in the refractory cement decomposes to generate gas. After the product is unpacked, a large number of pores will be generated around the cold joint roll neck; After the molten iron is poured, its solidification speed is fast, and the collapsed refractory cement particles cannot escape smoothly and float up to the riser end of the roll neck, resulting in slag inclusion; It takes a long time to repair the entire roll; 4) The matching surfaces of the overflow box and the riser box currently used are all flat structures, the positioning accuracy is poor, and the operation is complicated. Every time a box ring is matched, the level and verticality need to be measured, and it is easy to mistake the box ; 5) A large amount of molten iron needs to be used for flushing

And with the change of casting boundary conditions, such as the amount of molten iron casting, casting roll neck section size, temperature, humidity, etc., the original cold welding process cannot meet the current mass production mode, nor can it Meet product quality requirements

Images