Novel full-automatic online cold welding repairing process for roll squeezers

Abstract

The invention discloses a novel full-automatic online cold welding repairing process for roll squeezers. The novel full-automatic online cold welding repairing process is characterized by comprising steps of (1), pre-treating roll surfaces of cement squeeze rolls to remove fatigue layers, welding check rings at two ends of each roll surface and enabling the corresponding check rings and each roll surface to be located on the same curved surface; (2), checking the roll surfaces to determine whether cracks are formed on the roll surfaces or not, grinding crack positions of the roll surfaces to remove the cracks, and performing repair welding on pits until the pits are filled; (3), performing buildup welding on the roll surfaces by means of automatic open arc welding; (4), removing the check rings and grinding and leveling the roll surfaces. The novel full-automatic online cold welding repairing process has the advantages that the buildup welding repairing quality can be guaranteed, the rolls of the roll squeezers do not need to be detached, stress relieving measures such as heating and heat insulation are omitted in buildup welding procedures, accordingly, working procedures can be greatly simplified, the construction cost can be greatly reduced, and energy can be saved.

Description

technical field [0001] The invention relates to the technical field of the cement industry, in particular to a repairing process of a cement extrusion roller of a roller press. Background technique [0002] The roller press is a kind of high-efficiency, energy-saving and widely-used grinding equipment imported from abroad in the early 1990s. It is suitable for the grinding of cement raw materials and clinker. A pair of extrusion rollers squeezes materials 50~300t / h, 24h continuous work, the material bears a pressure of 100~300MPa between the two rollers, and the surface of the crushing roller is subject to periodic high-stress abrasive wear and fatigue damage. Therefore, the surfacing layer on the roller surface is required to have better abrasive wear resistance and higher hardness. Generally, the hardness is required to be above HRC55, and it has good toughness, so as to avoid severe wear or peeling of the roller surface. The long-term use of the roller press will serio...

AI Technical Summary

Problems solved by technology

The traditional welding repair method adopts the submerged arc automatic surfacing method. The submerged arc welding has the characteristics of smooth and beautiful weld bead and high efficiency, but the heat input during the welding process is large, and the welding stress on the equipment is very large. If effective The way to completely remove the stress generated during the welding repair process will cause serious deformation and damage the internal structure of the equipment during the use of the equipment, resulting in a large number of cracks, delamination or even fracture

In the traditional repair process, in order to eliminate the stress, it is generally required to heat the base metal, keep it warm, and anneal the equipment as a whole after welding. However, the general roller press and large equipment are large in size and heavy in weight, and the equipment needs to be restructured. Heating requires large-scale heating furnaces and equipment, which requires huge investment and low efficiency, and the disassembly and assembly of large-scale equipment is complicated. The cost and construction period are often unaffordable for enterprise production, so online is often chosen (neither disassembly is directly performed on the equipment for repair) However, due to the limited space of general equipment, flame heating is often used. The flame heating efficiency is low. To achieve effective and uniform heating of the equipment, it is very difficult to keep warm, and the working environment after heating is very bad. Working at high temperature for a long time, it is difficult to ensure that the welding work can be carried out with quality and quantity

In addition, after welding, the whole roller needs to be heated to more than 400 degrees for annealing, which is difficult for general equipment, so in the actual work process, it is often heated to about 200 degrees to keep warm, and the heat preservation measures are also difficult to put in place, so welding The quality is difficult to guarantee, and the repair effect is good and bad

To sum up, the submerged arc welding repair has the following disadvantages that cannot be completely solved: (1) The heating and heat preservation measures cannot be properly implemented, and the welding stress cannot be completely eliminated; (2) The working environment after heating is harsh, and workers cannot work stably for a long time. There are hidden dangers in welding quality; (3) There are many construction procedures and quality control points, and slight mistakes will easily cause quality defects; (4) Submerged arc welding needs to add flux to protect the weld bead, which is inconvenient in online repair and construction efficiency (5) It is easy to damage the seal and transmission system of the equipment during the heating process

Images