In order to evaluate the wear resistance and service life of Bei Ma multiphase wear-resistant cast steel lining plate, the industrial operation experiment of the prepared lining plate was carried out on the HP800 cone crusher in the ore breaking workshop of Qidashan Iron Mine of Angang Group Mining Co., Ltd. during the experiment, the height of the caliper adjusting the lining plate was measured in the workshop after a certain period of operation, In the ore breaking workshop, this index is usually used to understand the wear of the lining plate, monitor and record the working current of the cone crusher, and the recording results are shown in Figure 1. It can be seen that the Bei Ma multiphase wear-resistant cast steel lining plate is out of service due to reaching the target service life and preventing damage to the machine body (not scrapping the lining plate). The cumulative ore breaking time is 209 hours and 51 minutes, and the final measured height on site is about 26.5cm (generally between 15cm-22cm). It can be seen from Figure 1, According to the motor current trend chart in the central control room, the current is stable and the equipment operates normally. The service life of bainitic Martian multiphase wear-resistant cast steel lining plate exceeds the average service life of domestic lining plate (about 135 hours) by more than 50%.
Disassemble the Bei Ma multiphase wear-resistant cast steel liner after installation and assessment. The morphology of the liner after disassembly is shown in Figure 2. According to the dynamic cone liner after installation and assessment, the liner is worn evenly, and there are still thicker dimensions that have not been worn. It can be seen from figure 2B that there are some holes on the surface. It is analyzed that there are shrinkage holes in the lining plate during the casting process. It is necessary to strictly monitor the casting quality of the lining plate in the subsequent casting process. From the fixed cone liner after installation and assessment, figure 2D shows that a lot of mineral particles are pressed into the inner working face of the liner, which is related to the low hardness of the liner, but the overall size has not changed much. Therefore, further improving the control ability of casting and heat treatment of Bei Ma multiphase wear-resistant cast steel lining plate is expected to effectively reduce the number of shrinkage cavities and embedded ore particles, so as to further improve the service life of the lining plate.
Measure the thickness of moving cone and fixed cone lining plate of bainite Martian multiphase wear-resistant cast steel after installation and assessment, so as to describe the position of the worn lining plate surface, and take samples at different heights of the same circumferential position on the circumference for mechanical property test. The specific sampling method is shown in Figure 2.
It can be seen that the mechanical properties of different positions of Bei Ma multiphase wear-resistant cast steel lining plate fluctuate little after service. The tensile strength is between 1209-1531mpa, the average value is 1311mpa, the yield strength is between 1108-1373mpa, the average value is 1188mpa, and the impact energy is between 26.9-39.7j, The average value is 34.2j, the hardness is between 43.8-52.9hrc, and the average value is 46.9hrc. The average values of the four key mechanical properties meet the index requirements mentioned above. It shows that the hardenability and homogeneity of the lining plate are good and can meet the performance index requirements.
On each cut lining plate fragment, the positions 1-2, 2-2, 3-2, 4-2 and 5-2 are respectively selected for metallographic structure observation. The results are shown in Fig. 3. It can be seen that the microstructure at different positions of bainite martensite composite wear-resistant cast steel lining plate is composed of bainite, martensite and residual austenite, The five areas have a certain degree of unavoidable component segregation in large casting.
The wear surface of bainite Martian composite wear-resistant cast steel liner is observed by SEM. The results are shown in Figure 4. It can be found that after industrial application, the wear morphology of bainite Martian composite wear-resistant cast steel liner is similar to that of three-body impact abrasive wear test after salt spray corrosion revealed by four-dimensional wear. The typical wear mechanisms are furrow, extrusion accumulation, strain fatigue, crack Embedded abrasive particles and embedded rust show that the overall wear resistance of the lining plate of this material is uniform, and the service life of different positions is not different, which is conducive to the extension of the overall service time of the lining plate.
