alloying elements on AISI 4140
alloying elements on AISI 4140
(OP)
Dear experts,
I've just done re-heat the AISI 4140 with the hardness result still didn't reach the maximum. The investigation found that the chrome is 0,7% which is should be on the range 0,9 to 1,2 % as the standard for AISI 4140. Is there any explanation or relation between the alloying element (with a little bit less form the standard range such as 0,7 of 0,9%) to the material properties?
Thanks in advance,
epan
I've just done re-heat the AISI 4140 with the hardness result still didn't reach the maximum. The investigation found that the chrome is 0,7% which is should be on the range 0,9 to 1,2 % as the standard for AISI 4140. Is there any explanation or relation between the alloying element (with a little bit less form the standard range such as 0,7 of 0,9%) to the material properties?
Thanks in advance,
epan





RE: alloying elements on AISI 4140
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"It's better to die standing than live your whole life on the knees" by Peter Mayle in his book A Good Year
RE: alloying elements on AISI 4140
Where are you getting the 0.90-1.20 range?
For AISI 4140H, the Cr range is 0.75-1.20.
If you consider a check analysis tolerance of 0.05% on Chromium, you result may not be out of range.
As arunmrao posted, we need more information.
rp
RE: alloying elements on AISI 4140
Also, I noticed you only reported Cr content to one digit. Did you get composition using a quantitative method (such as OES) or from a semiquantitative method such as EDS or portable XRF? I would not trust values obtained using semi-quant methods for this purpose.
Aaron Tanzer
www.lehightesting.com
RE: alloying elements on AISI 4140
For the re-heat I do follow the step as referenced from ASM handbook vol.4 heat treating for ultra high-strength steels, with the section thickness 25mm, hardening to 870 degC, with oil quenching.
For Cr, some references said it's 0.9-1.2 and 0.8-1.1 I just pick the bigger one to have the different one.
I had the composition by OES method, the actual Cr is 0,734%, and the rest of the element is on the range even some is on the lowest range.
RE: alloying elements on AISI 4140
Was the hardness test performed at the surface?
If not, at what depth were the readings taken from?
Ron Volmershausen
Brunkerville Engineering
Newcastle Australia
http://www.aussieweb.com.au/email.aspx?id=1194181