POSSIBILITY OF IMPROVING CORRECTIONS FOR ROCKWELL HARDNESS VALUE OBTAINED ON CONVEX CYLINDRICAL SURFACES
Abstract
Evaluation of measurement uncertainty when correction value in ISO 6508 and ASTM E18 is applied is disputable. Using corrections, discrete and without uncertainty, is a difficulty to provide best measurement capability related to the application using the corrections. In order to study the possibility to complete the corrections to be in term of equations together with uncertainty of the equation, cylindrical shafts at nominal hardness 20 HRC, 40 HRC, and 60 HRC with diameter 6 mm to 38 mm were supplied in this experiment. In addition, this study includes the accuracy of the corrections by considering the effect of frame deformation of flat anvil and v anvil, effect of misalignment between indenter and cylindrical shaft, as well as effect from indenters. The corrections in form of equations for nominal hardness 20 HRC, 40, HRC, and 60 HRC along with uncertainty less than ±0.25 HRC are reported. This confirms the possibility to revise the corrections with uncertainty for convex cylindrical surfaces in ISO 6508 and ASTM E18.
Event details
- Event
- HARDMEKO 2010
- Technical Committee
- TC5
- Place
- Pattaya, THAILAND
- Time
- 21 November 2010 - 25 November 2010
- Website
- http://imeko2010.nimt.or.th/