Carbon equivalent F65
Carbon equivalent F65
(OP)
My client asks for a carbon equivalent CE(IIW) of 0.40 for F65 forging flanges with the thickness of the weld neck of 25mm.
My supplier can not provide that CE and instead offers a CE of 0.44 (carbon content of 0.16%).
As far as I know, higher carbon equivalent means that the steel is less weldable, but in this case what will be the actual consequences if I accept a CE of 0.44 instead of 0.40?
What I can think is that I may need to use preheat for welding, is it correct?
How can I determine the preheat temperature?
Is there any other consequences beside possible need of preheat?
Bhoro
My supplier can not provide that CE and instead offers a CE of 0.44 (carbon content of 0.16%).
As far as I know, higher carbon equivalent means that the steel is less weldable, but in this case what will be the actual consequences if I accept a CE of 0.44 instead of 0.40?
What I can think is that I may need to use preheat for welding, is it correct?
How can I determine the preheat temperature?
Is there any other consequences beside possible need of preheat?
Bhoro





RE: Carbon equivalent F65
You can get a guide for preheat temperature in ISO TR 17844
Steve Jones
Materials & Corrosion Engineer
http://www.linkedin.com/pub/8/83b/b04
RE: Carbon equivalent F65
Thanks for the response.
Forget to mentioned the forging thickest section is 200 mm. According to a number of suppliers we talked to that is the reason a CE 0.44 is needed.
Regarding the other aim of the CE restriction as you mentioned
"...may also be a means of controlling material properties for resistance to certain degradation mechanisms...",
I guess one of them is to limit the hardness right?
Any other degradation mechanisms influenced by CE of 0.44?
RE: Carbon equivalent F65
Degradation mechanisms that could be affected by chemical composition:
- H2S cracking
- fracture
- hydrogen embrittlement
Steve Jones
Materials & Corrosion Engineer
http://www.linkedin.com/pub/8/83b/b04
RE: Carbon equivalent F65
RE: Carbon equivalent F65
RE: Carbon equivalent F65
This depends on heat treatment procedure. I used to find problem with low impact value on this material...
RE: Carbon equivalent F65
A bigger but less obvious concern is the use of doping with V and/or Nb to achieve properties in thick sections. Caused me much grief one time with stress relief cracking. One of their diry secrets methought.