Test unit: Foundry Laboratory, Material College, Huazhong University of Science and Technology
One sample of floating seal ring with the inner diameter of 366mm is subject to test for the hardness and the microstructure of its section.
2 Test sample preparation
Cut two pieces off from the sample and prepare them by resin mounting; and then test the microhardness and Rockwell hardness after preliminary grinding, accurate grinding and polishing; observe the microstructure after corroding the samples by 5% nitric acid alcohol. The durometer is the Digital Vickers Hardness Tester of American Buehler Company, with 100gf of loading force.
3 Hardness test result
The location of test point is shown as Figure 1
Test result is shown in Table 1.
Table 1 Sample Hardness Distribution
Rockwell hardness (HRC)
Vickers hardness (HV)
3Relative to test point 2, 1mm shift to the left
4Relative to test point 3, 1mm shift to the left