Carbon Equivalent Limitation for Weldability of Steels
Carbon Equivalent Limitation for Weldability of Steels
(OP)
Hell, in Wikipedia Carbon Equivalent Limitation for Weldability of Steels is defined as:
Carbon equivalent (CE) Weldability
Up to 0.35 Excellent
0.36–0.40 Very good
0.41–0.45 Good
0.46–0.50 Fair
Over 0.50 Poor
I looked through AWS D1.1 and AWS D1.4, but i failed to find the definition of Carbon equivalent for weldability of steel. So I want to know in which code could i find the definition for Carbon Equivalent Limitation for Weldability of Steels
Thank you!!
Carbon equivalent (CE) Weldability
Up to 0.35 Excellent
0.36–0.40 Very good
0.41–0.45 Good
0.46–0.50 Fair
Over 0.50 Poor
I looked through AWS D1.1 and AWS D1.4, but i failed to find the definition of Carbon equivalent for weldability of steel. So I want to know in which code could i find the definition for Carbon Equivalent Limitation for Weldability of Steels
Thank you!!





RE: Carbon Equivalent Limitation for Weldability of Steels
FAQ330-1077: Carbon Equivalent Equations for Weldability of Steels
RE: Carbon Equivalent Limitation for Weldability of Steels
Steve Jones
Materials & Corrosion Engineer
http://www.oilandgaspeople.com/cv/11499664
http://www.linkedin.com/pub/8/83b/b04
RE: Carbon Equivalent Limitation for Weldability of Steels
RE: Carbon Equivalent Limitation for Weldability of Steels
A simple definition of weldability is the ability to be welded without cracking. A simplistic definition, but good enough for many situations.
In general, as the CE increases there is more concern for cracking due to decreases in ductility (as strength and hardness increase, ductility decreases) and increased potential for cracking. One of the more serious issues and potential causes for cracking problems in a carbon steel alloy is the diffusible hydrogen introduced into the molten weld puddle from various sources such as flux coverings, granulated flux, surface contamination, etc. One means of reducing the potential for hydrogen induced cracks is to ensure the weld is ductile, i.e., ensure the microstructure isn't hard and brittle. Other activities include preheating before welding, maintaining high interpass temperatures, and performing post weld heat treatments to reduce residual stresses.
When the CE is low, little if any preheat is required. As CE increases, higher preheat is needed, as the CE increases even more, low hydrogen welding practices are needed in addition to high preheat and maintenance of high interpass temperature, etc.
Each carbon equivalency has its own set of guidelines. It is important to use the proper guidelines and do not apply the guidelines intended for one CE formula to different formula.
Best regards - Al
RE: Carbon Equivalent Limitation for Weldability of Steels
RE: Carbon Equivalent Limitation for Weldability of Steels
RE: Carbon Equivalent Limitation for Weldability of Steels
1. Carbon Equivalent of Cast Iron (Ceq) – element: weight %
Ceq/ = C + (Si + P) / 3
2. Carbon Equivalent of Carbon Steels (Ceq. %) – element: weight %
(1) Ceq = C + Mn /6 + (Cr + Mo + V) /5 + (Ni+Cu) /15 ; BS 2642 and IIW
(2) Ceq : C + Mn /4 + Ni /20 + Cr /10 + Cu /40 + Mo /50 + V /10 ; AWS
(3) Ceq = C + Mn /6 + Si /24 +Ni /40 + Cr /5 + Mo /4 + V /14 ; Japan JIS G 3106 & 3115
(4) Ceq = C + F [Mn/6+Si/24+Cu/15+Ni/20+(Cr+Mo+V+Nb)/5 + 5B] ; CSA Z245.1
F is a factor per Ceq.
(5) Others ; Several different formulas from lab studies.
3. Carbon Equivalent (Crack Parameter in Welding -Pcm , %)
Pcm is more appropriate than conventional carbon equivalent (Ceq) for steels, such as low carbon steels, HSLA (high strength low alloy steels) or TMCP (thermo mechanical controlled process steels). Pcm carbon equivalent formula was developed for steels with low carbon contents (<0.10%) and with tensile strengths of 60 to 130 ksi in Japan.
Pcm = C + Si /30 + (Mn + Cu + Cr) /20 + Ni /60 + Mo /15 + V /10 + 5 x B
Thomas Eun
RE: Carbon Equivalent Limitation for Weldability of Steels