Arc energy and heat input

per EN 1011-2, Annex D

Input

mm
°C
s

Result

Arc energy
E = 1.43kJ/mm
Heat input
Q = 1.15kJ/mm
Transition thickness
17.60mm
Heat flow
three-dimensional

The plate is thicker than the transition thickness.

Shape factor per EN 1011-2, Table D.1.

Adjust factors

Leave empty to use the table values. Custom values make sense for processes, arc types or welding positions the tables do not cover — but the result is then no longer covered by the standard.

table value 0.80
table value 1.00
table value 1.00
Background and formulae

The cooling time t8/5 is the time a weld run and its heat-affected zone take to cool from 800 °C to 500 °C. It largely governs the mechanical properties of the joint. This calculator implements the method of EN 1011-2, Annex D.

The two quantities

Arc energy E is the energy supplied per unit length. Heat input Q is the share of it that actually reaches the workpiece: Q = η · E. Since η ≤ 1, Q ≤ E always holds. The cooling time is governed by Q.

Formulae

Three-dimensional heat flow (thick plate)

t8/5 = (6700 − 5 T0) · Q · [ 1/(500−T0) − 1/(800−T0) ] · F3

Two-dimensional heat flow (thin plate)

t8/5 = (4300 − 4,3 T0) · 105 · (Q/d)2 · [ (1/(500−T0))2 − (1/(800−T0))2 ] · F2

Transition thickness — Below this thickness the two-dimensional case applies, above it the three-dimensional one. The calculator selects automatically.

dü = √( (4300−4,3 T0) · 105/(6700−5 T0) · Q · [ 1/(500−T0) + 1/(800−T0) ] )

Thermal efficiency factors

Per EN 1011-1:2009, Table 1.

Process η
SAW UP (12) 1.00
Manual metal arc welding with stick electrode E (111) 0.80
Metal active gas welding (MAG) MAG (135) 0.80
Metal inert gas welding (MIG) MIG (131) 0.80
Tungsten inert gas welding (TIG) WIG (141) 0.60

Shape factors

F2 applies to two-dimensional, F3 to three-dimensional heat flow. Where the standard gives a range, this calculator uses the lower bound — which yields the higher required energy. The full range is shown with the result.

Joint type F2 F3 Source
Deposit weld 1.00 1.00 EN 1011-2
1. and 2. fillet weld on T- or cross joint 0.45–0.67 0.67 EN 1011-2
3. and 4. fillet weld on cross joint 0.30–0.67 0.67 carried over
Fillet weld on corner joint 0.90–0.67 0.67 EN 1011-2
Fillet weld on overlap joint 0.70 0.67 carried over
Root pass of V-joints 1.00 1.00–1.20 carried over
Root pass on double-V-joints 0.70 0.70 carried over
Center passes on V- and double-V-joints 0.90 0.90 EN 1011-2
Cover passes on V- and double-V-joints 0.90 0.90 EN 1011-2
I-seam, 'Layer-counter layer welding' 1.00 1.00 carried over

Limits of the method

  • The concept applies to joints of equal plate thickness. For unequal thicknesses it gives an indication only.
  • The cooling time is a window, not a lower limit: cooling too fast hardens the material, too slow costs toughness. For filler and capping passes in unalloyed and low-alloy steels EN 1011-2 typically quotes 10 to 25 s.
  • This calculation does not replace a welding procedure test.

Sources

  • EN 1011-2:2001+A1:2003, Annex D
  • EN 1011-1:2009, Table 1
  • ISO/TR 18491:2015