| Doc. No: KKM/GWI/38 | WORK INSTRUCTION FOR ROCKWELL HARDNESS TESTING |
| Rev. No.: 01 | |
| Rev. Date: 20.11.2012 |
- Checking the performance of Hardness Tester:
- (Observation of Identification marks on the test piece)
- Ball Indenter with 100 kg, test load for HRB scale (Preliminary load-10 kg).
- Diamond Indenter with 60 kg, test load for HRA scale (Preliminary load-10 kg).
- Diamond Indenter with 150 kg, test load for HRC scale (Preliminary load-10 kg).
- Diamond Indenter with 15 kg, test load for HR 15N scale (Preliminary load-3 kg).
- Diamond Indenter with 30 kg, test load for HR 30N scale (Preliminary load- 3kg).
- Diamond Indenter with 45 kg, test load for HR 45N scale (Preliminary load- 3kg).
- Grind the sample on emery paper to make it free from oxide, or any foreign matter, also avoid any alteration of surface hardness due to hot or cold working.
- Ensure that thickness of pc. Under testing shall be at least 10 times than the depth of the indentation. No deformation shall be visible on the opposite side of testing surface. (Refer ASTM E 18-02).
- Place the sample on the anvil (on flat anvil if the component is flat & V-anvil if the component is round). Correction factor to be added if the surface is round & subtracted if the surface is concave (Refer ASTM E 18-02 Table 11, 12 & 13).
- Bring the surface of part to be tested close to the indenter.
- Turn the lever at right hand side backward so that total load is brought into action without any jerk:
- For material, which shows some time dependent plasticity, total test duration shall be applied up to 5 seconds.
- For material, which shows considerable time dependent plasticity, total test force shall be not less than 10 seconds & not more than 15 second
- Record the observations.
- Refer standards ASTM E 18-02.