ASM Charpy Impact Data

[metalman8357]

ASM has published reference Charpy impact energy values for a certain alloy of steel. I'm looking to determine a ball park for the impact strength at a hardness of 40HRC. The data table has various charpy energies at different temperatures and different hardness values. My question is, can I plot impact energy as a function of hardness and roughly interpolate what the impact energy will be at my hardness value? Or, since these values are taken at different temperatures does that change things? Again, this is just to get a rough estimate. I'm a recent college grad working in the industry so go easy on me guys!

Thanks,
M

 

[metengr]

metalman8357;
The simple answer to your question is no. Charpy V-notch impact values are alloy specific (chemical composition) and heat treatment specific. There are CVN trend curves for carbon steel as a function of carbon content for the same grade of steel (plain carbon) with no specific heat treatment to demonstrate changes in upper/lower shelf and transition temeprature shifts. There is also a hardness curve that demonstrates the effect of increasing carbon content on hardness of martensite for plain carbon steel. However, to try to develop a master curve that shows expected CVN as a function of hardness for a certain plain carbon or low alloy steel grade would be a significant stretch.

 

[metalman8357]

That makes complete sense, thank you.

 

[EdStainless]

That said, for most engineering alloys you can find some impact data. So you might be able to compare toughness of various grades of steel, all heat treated to 40RC, tested at room temp.
It is important to realize though that different alloys will have different temperature dependence.

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