Carbon Equivalent Number for different steel

[mariolucas75]

Dear All,

Carbon Equivalent (CE) number defines the weldability of the steel, the lower CE the better weldability,
Is there a table for CE for known steel grades? and if no why ?
There is a formula for calculation CE=C+(Mn/6)+((C+Mo+V)/5)+((Ni+Cu)/5)

If we take for example a 316L SS that is having following composition:
(C)<0.03%
(Mn): ≤ 2.00%
(Cr): 16.00 - 18.00%
(Mo): 2.00 - 3.00%
(Cu): ≤ 0.75%
(Ni): 10.00 - 14.00%

Considering the average values:

• Cr = 17.00%
• Mo = 2.50%
• Cu = 0.75%
• Ni = 12.00%

Gives for 316L CE≈5.11
However in for example "API 577 welding processes, inspection and metallurgy" paragraph 10.8.2. metallurgy and weldability (and other sources) it says steel with CE<0.35 have excellent weldability, steels with CE >0.5 poor weldability.

316L is considered a steel with an excellent weldability whereas its calculated CE turned out to be 5.11 ?
What do i miss ?

 

[pierreick]

Hi,
You may need to divide your figures by 100!
Pierre

 

[SJones]

CEV is applicable to carbon and low alloy steels only. Austenitic stainless steel is a different animal. The value is an indicator of hardenability and gives a guide to the measures that may need to be instituted to reduce the likelihood of weld cracking.

 

[akpipelineengr]

https://en.wikipedia.org/wiki/Equivalent_carbon_content

 

[EdStainless]

Wrong alloy for that formula.
Weldability of austenitic alloys is evaluated differently.

 

[kingnero]

Is there a table for CE for known steel grades? and if no why ?

The EN/ISO steel fabrication standards give for (almost) each alloy the max. CE. Carbon steel that is, not stainless steel!
As there is a range for each alloying element, there's also going to be a range for CE. Lower limit isn't of much use, so they only give the max. value.