Charpy unnotched 2.5x10x55 testing service?

BluntCut MetalWorks

Knifemaker / Craftsman / Service Provider
Joined
Apr 28, 2012
Messages
3,462
About 3 years ago, a vendor tested 5 sets of my knife-steels v-notched specimens. It was quite obvious, results were very low and force spread within 3 ft-lbs range. So I asked that vendor to perform unnotched specimen in the future - got a 'yes'. Since last week, that vendor is unwilling and I couldn't find any other vendor offer/willing to perform unnotched knife-steels. I can't even find - 3mm radius c-notch testing service for high strength (knife) steel either.

I would like to test 2 set of 1095 specimens, 58.5rc and 60rc. Plan for next 2 months, 1 to 2 sets per steel [ 1095, 8670, 52100, w2,440c].

Suggestion/idea on unnotch charpy testing services? btw - I'd pm Larrin Larrin but no reply yet.

Alternatively, I'm starting to think about building a free fall impactor (4 lbs carbide hammer, 6 ft distance => 24 ft-lbs, increase mass if needed higher impact force). Result would then linear translate to standard 10mm thick. Thoughts?
 
Dumb it down for me please...

What is "v-notch" and "unnotched"?

And what is this test for? Impact/shatter resistance?
 
Dumb it down for me please...

What is "v-notch" and "unnotched"?

And what is this test for? Impact/shatter resistance?
In materials science, the Charpy impact test, also known as the Charpy V-notch test, is a standardized high strain rate test which determines the amount of energy absorbed by a material during fracture... https://en.wikipedia.org/wiki/Charpy_impact_test

Where unnotched = the specimen without a 'V' scored/cut into it, more or less a pre-established stress riser.

-------
Thanks Larrin Larrin for your helpful replied to my PM :thumbsup:
 
Thanks J! Cool article (I scanned it), look like a cool way to test bulk ductile steel. This sure encouraging me to build a vertical impactor would more applicable to knife steels (very high tensile strength). For testing 8670, I would need to increase hammer weight to 10 lbs [for ~60 ft-lbs, E=mgh=(1/2)mv^2 ] I will keep this author in mind, especially when ran into problems with the testing contraption.
 
Back
Top