Correlation between C-Mn balance and Impact test properties

[abramb]

Hi, maybe someone can help me please.
Talking about low carbon Mn-Ni-Mo steels, i.e. SA-508 Gr.1A.
Forged material especially.

I am looking for articles and papers, about the effect of different C-Mn balance only (no through Nb, V, Ti additions) on the impact properties.
I am looking in the detail about the effects on microstructure, DBTT (Ductile-Brittle Transition Temperature) temperature, and the Impact values.

I found something on JAMME, but it would
It would be helpful also your personal experience.



Thank you very much in advance.
A.

Attilio Brambilla
Material Engineer

http://it.linkedin.com/pub/attilio-brambilla/25/465/544

 

[metengr]

The bottom line - you are looking for actual CVN curves for SA-508 class materials.

Regarding C-Mn, both have an effect on CVN behavior. Carbon is probably the most influential parameter that affects CVN behavior. Higher carbon content results in lower CVN values (upper and lower shelf s) and shifts the DBTT to higher temperatures.
Manganese is noted as a strengthener, deoxidizer and sulfur scavenger for carbon steels which promotes higher CVN values for the upper shelf and shifts the DBTT to lower temperatures, which is good.
Thus, you have competing forces between carbon content and manganese content on CN behavior. In the end, carbon content wins, which is the reason why other alloying elements are deliberately added to promote increased toughness (like nickel) or fine grain practice (aluminum or other micro-alloy elements).

 

[metengr]

Sorry, forgot to copy my last part of the previous post - the optimum Mn/C ratio should be 3:1.
From the literature I have seen, it was reported for each increase in 0.1% by mass of carbon content the DBTT is raised by 14 deg C, for each increase in 0.1% by mass of Mn content, the DBTT is lowered by 5.5 deg C.

 

[abramb]

Thanks a lot for the reply metengr.

Attilio Brambilla
Material Engineer

http://it.linkedin.com/pub/attilio-brambilla/25/465/544

 

[abramb]

@ Metengr: can you suggest me some article to read about this issue, please?


Attilio Brambilla
Material Engineer

http://it.linkedin.com/pub/attilio-brambilla/25/465/544

 

[metengr]

http://books.google.com/books?id=Sg...manganese contents on notch toughness&f=false

http://www.sut.ac.th/engineering/metal/pdf/MechMet/14_Brittle fracture and impact testing.pdf

You can perform additional searches and find more information.

 

[abramb]

Thanks again metengr!
A.

Attilio Brambilla
Material Engineer

http://it.linkedin.com/pub/attilio-brambilla/25/465/544