Abstract
Содержание
- Introduction
- 1. Main content and results
- 2. Analysis of design features
- 3. Develop an integrated technological process
- 4. Experimental evaluation of erosion damage
- conclusions
- List of sources
Introduction
In this paper, the total resource of knives of production equipment has been increased, which are operated under conditions of the action of erosion-corrosive effects of the environment, due to the increase in the overhaul life and the number of restored blades on the basis of complex DWD, formation of FOP and the required structure of the technological process.Modern blades of knives are made of special alloys with a complex spatial shape of the blade, while they have thin entrance and exit edges. The blade of the knife is one of the most labor-consuming products. This is due to the fact that complex technologies and expensive materials are used for their manufacture, and a certain number of knives is used in one equipment.
To increase the resource and reliability of the operation of the knives of production equipment, a whole complex of different finishing-strengthening operations is applied. At the same time, the technologies used do not allow to exclude constantly acting uneven fractures of the surfaces of the blade of the knife, arising from the erosion-corrosive effects of the external environment
The unevenness of erosion-corrosion destruction of the blade's blade surfaces is due to its spatial shape and the kinematics of motion, the action of liquid particles and other substances. The destruction of the blade usually begins with the input edge in the intersection of the input and peripheral edges.
1. Main content and results
In the paper, studies of the features of erosion-corrosion damage of knives of production equipment on the surfaces of blades have been carried out. These studies made it possible to establish that when the equipment is used, the coatings of the knives are not evenly destroyed. Even with their long operation, part of the coating remains on the surfaces of the blades. Moreover, during the operation of the blade, in the places of complete destruction of the coating, an intensive destruction of the main material of the knife blade (body) occurs, where the coating is not destroyed, the main material of the blade is not subject to damage. These processes of uneven corrosion-erosion failure lead, in a number of cases, to loss of maintainability of knives.
For the implementation of coatings, an algorithm for synthesizing the complex technological process of performing FOP on blades of production equipment has been developed. Here, the process has two return cycles for applying coatings to the blades. To perform an integrated technological process for each blade, the execution of three stages. In the work a structural synthesis of the universal complex technological process of finishing-hardening knives is performed. Based on this structure can be used to restore knife blades with FOP. In this case, each time before the coating is sprayed, polishing and ultrasonic cleaning of the blade surfaces are performed.
A comparative experimental evaluation of erosive destruction of vacuum ion-plasma coatings of knife blades is performed.
2. Analysis of design features
The unevenness of erosion-corrosion destruction of the blade's blade surfaces is due to its spatial shape and the kinematics of motion, the action of liquid particles and other substances. The destruction of the blade usually begins with the input edge in the intersection of the input and peripheral edges.
To improve the operability and maintainability of the knives of production equipment in conditions of uneven erosion-corrosive influences of the blade environment are implemented on the basis of the principle of a complete one-time destruction of the coating over the entire surface of the blade.
This will allow the following:
1. Eliminate the destruction of the main material of the blade in conditions of uneven effect of erosion-corrosion wear, over the surface of the knife blade.
2. Increase the life of the equipment before overhaul by increasing the operational potential of FOP to the limit value.
Page 3. Ensure the possibility of multiple use of the blade due to their multiple restoration during operation.
4. Reduce the duration of removal of residual coating from the surfaces of the blades by providing a one-time complete destruction of the coating during operation.
Page 5. Apply a new approach to increasing the resource
The complex technological process for the realization of functionally oriented coatings for knives consists of three stages (Figure 1). In Fig. 1 is a graph of the complex technological process of FOP implementation on knife blades. At the second stage of the technological process the following operations are performed: polishing, ultrasonic treatment and spraying of the i-th FOP. On the graph, the arrows show the direct and return sequence of the operations of the technological process. Here, before each i-th process of FOP realization, it is necessary to perform polishing and ultrasonic processing of the previous coating surface to ensure adhesion material of the coated blade and cohesion of various coatings among themselves.
Figure 1 - The graph of the complex technological process of FOP implementation on blade knives production equipment.
3. Develop an integrated technological process
The complex technological process for the realization of functionally oriented coatings for knives consists of three stages (Figure 1). In Fig. 1 is a graph of the complex technological process of FOP implementation on knife blades. At the second stage of the technological process the following operations are performed: polishing, ultrasonic treatment and spraying of the i-th FOP. On the graph, the arrows show the direct and return sequence of the operations of the technological process. Here, before each i-th process of FOP realization, it is necessary to perform polishing and ultrasonic processing of the previous coating surface to ensure adhesion material of the coated blade and cohesion of various coatings among themselves.
For the implementation of coatings, an algorithm for synthesizing the complex technological process of performing FOP on blades of production equipment has been developed. Here, the process has two return cycles for applying coatings to the blades. To perform a complex technological process, three stages are performed for each blade. In the work a structural synthesis of the universal complex technological process of finishing-hardening knives is performed. Based on this structure, a selection of specific process variants for the restoration of knife blades with FOP is performed. At the same time, polishing and ultrasonic cleaning of the blade surfaces were performed each time before the coating was sprayed.
Experimental evaluation of erosion damage
A comparative experimental evaluation of erosive destruction of vacuum ion-plasma coatings of knife blades is performed. The analysis of the obtained results made it possible to establish that the value of the erosion destruction of the coating according to its thickness is in direct proportion to the time of wear (Fig. 2).
Figure 1 – Count of complex technological process of FOP implementation on blades of production equipment.
animation 1 – direct proportional dependence
Where is Ax- the working of the blade of the knife before its restoration (hour);
xh - coating thickness in the given zone of the compressor blade (hxmax = 14 ?m for the first stage);
k1, k2 - coefficients of uneven wear of the coating on the surface of the knife blade.
Conclusions
Thus, the analysis of knife blades with FOP working in conditions of variable erosion-corrosion wear is performed. The developed technological support allows to form the structure of the technological process for the implementation of FOP blade blades, Operating under the conditions of the surface-changing erosion-corrosive destruction of the blade. And also carried out experimental studies have shown that the process of erosion destruction of FOP blades obeys the law of direct proportional dependence on the duration of environmental influences.