Pre-heat Estimator

Determine the recommended minimum pre-heat temperature based on the material's Carbon Equivalent (CE) and thickness to prevent cold cracking.

Calculate CE here if unknown.
Low Hydrogen processes include TIG, Solid MIG, or 7018 Stick. Standard includes 6010/6011 Stick or Flux-Core without basic slag.
Recommended Action
Minimum Pre-heat Temperature
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°F |

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°C

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Why Pre-heat?

Pre-heating slows down the cooling rate of the weld and the Heat Affected Zone (HAZ). This provides two critical benefits:

  • Prevents Martensite: Slower cooling prevents the formation of hard, brittle microstructures in the steel.
  • Hydrogen Diffusion: It allows trapped hydrogen gas (introduced from moisture or the arc) to diffuse out of the weld matrix before the metal locks it in place, preventing Hydrogen-Induced Cracking (Cold Cracking).
The Mass Quench Effect

Thick plates act as a giant heat sink. If you weld a 2-inch thick plate at room temperature, the surrounding cold metal will instantly suck the heat out of the weld (quenching it). This is why thickness is just as important as chemical composition.

Code Compliance: This calculator provides rule-of-thumb engineering estimates based on generalized CE tables. For structural or pressure vessel work, you must adhere strictly to the pre-heat tables in your qualified WPS (e.g., AWS D1.1 Table 3.3).