Charpy Energy vs. Hardness
Charpy Energy vs. Hardness
(OP)
Hi All,
The ANSI Z359.18 subcommittee is struggling with the practicality of doing charpy tests on small components that may be forged or stamped that cannot be machined into a standard Charpy sample (10mmx10mmx100mm).
I am wondering if there is a correlation between the charpy energy and the Rockwell Harness number, and whether I could specify a series of RHN vs. temperature as an alternative to Charpy testing.
Any reference materials or suggestions would be greatly apprecaited.
The ANSI Z359.18 subcommittee is struggling with the practicality of doing charpy tests on small components that may be forged or stamped that cannot be machined into a standard Charpy sample (10mmx10mmx100mm).
I am wondering if there is a correlation between the charpy energy and the Rockwell Harness number, and whether I could specify a series of RHN vs. temperature as an alternative to Charpy testing.
Any reference materials or suggestions would be greatly apprecaited.





RE: Charpy Energy vs. Hardness
RE: Charpy Energy vs. Hardness
RE: Charpy Energy vs. Hardness
RE: Charpy Energy vs. Hardness
When you say inverse correlation, is there any coefficent associated with the formula? Can you send me that formula?
Thanks for all.
RE: Charpy Energy vs. Hardness
The only sub-size CVN specs that I have seen are where someone has changed to an energy per unit area requirement as opposed to just the typical energy requirement. Is testing a full sized specimen totally out of the question, machine it from the raw material in the same final condition?
RE: Charpy Energy vs. Hardness
rp
RE: Charpy Energy vs. Hardness
RE: Charpy Energy vs. Hardness
In general, if the section is too small to obtain a sub-sized CVN, a Charpy test is not needed. Sure, thin materials can be brittle, but the CVN test is used to measure toughness under conditions of high constraint, and if the material is thin, you usually won't get a lot of constraint. In these cases, the ductility results from the tensile test (% El) will usually let you know if the material is too brittle for the application.
rp