FLAME METALLURGICAL, INC.
Carbon equivalent numbers (CE) can be calculated from various emphirical formulae to represent the relative influence of the combined effects of significant compositional elements in a hardenable steel influencing the material's hardenability and weldability.

Two different formulas are shown below for comparison. These calculations are 'rule of thumb' and should be verified by actual practice and testing. CE numbers provide a useful starting point for a proposed welding process specification or for application of an existing procedure to a new material. Note that the CE only considers the composition of the base material and not numerous other important welding factors such as section thickness or restraint.

Formula 1
CE( 1 ) = %C + %Mn/6 + %Ni/15 + %Mo/4 + %Cr/4 + %Cu/13

Estimated Preheat and Interpass temperatures from above CE( 1 ) :
CE( 1 ) < .45 ...... preheat optional
CE( 1 ) =.45 to .60 ... 200 to 400 F
CE( 1 ) > .60 ............ 400 to 700 F

Formula 2
CE( 2 ) = %C + %Mn/6 + (%Cr + %Mo + %V)/5 + (%Si + %Ni + %Cu)/15

Estimated Preheat and post heating requirement from above CE( 2 ) :
CE( 2 ) < .35 ...... usually requires no pre or post heating
CE( 2 ) =.35 to .55 ............... usually requires preheating
CE( 2 ) > .55 ......... usually requires pre and post heating

Input alloying elements wt% to try the CE formulas :
%C%Mn%Si%Cu%Ni%Cr%Mo%V

CE( 1 )  =   CE( 2 )  =