Research Article
Assessing the Hardness of Quenched Medium Steel Using an Ultrasonic Nondestructive Method
Table 2
Grain-size number and average grain size with different temperatures.
| Temperature (°C) | 760 | 800 | 840 | 880 | 920 |
| Grain-size number (200x) | 10.7 | 10.1 | 10.6 | 12.1 | 12.4 |
| Grain-size number (100x) | 8.7 | 8.1 | 8.6 | 10.1 | 10.2 |
| Average grain size (mm) | 0.0177 | 0.0218 | 0.0183 | 0.0108 | 0.0105 |
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