Weld Heat Input Calculator

Heat Input Formula:

\[ HI = \frac{V \times I \times 60}{S} \]

Heat Input (HI): kJ/mm

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is a Weld Heat Input Calculator?

Definition: This calculator determines the heat input during welding based on voltage, current, and travel speed.

Purpose: It helps welders and engineers control the thermal energy delivered to the weld, which affects weld quality and properties.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ HI = \frac{V \times I \times 60}{S} \]

Where:

\( HI \) — Heat input (kJ/mm)
\( V \) — Voltage (V)
\( I \) — Current (A)
\( S \) — Travel speed (mm/min)

Explanation: The product of voltage and current represents power, which is multiplied by 60 to convert to kJ/min, then divided by travel speed to get energy per unit length.

3. Importance of Heat Input Calculation

Details: Proper heat input control ensures adequate penetration, reduces distortion, and maintains mechanical properties in the heat-affected zone.

4. Using the Calculator

Tips: Enter the welding voltage, current, and travel speed. All values must be > 0 (speed must be > 0.01).

5. Frequently Asked Questions (FAQ)

Q1: Why is heat input important in welding?
A: Heat input affects weld penetration, cooling rate, microstructure, and mechanical properties of the weld.

Q2: What are typical heat input values?
A: For arc welding, typical values range from 0.5-2.5 kJ/mm depending on material and process.

Q3: Why multiply by 60 in the formula?
A: The factor converts volts × amps (watts) to joules/second to kJ/minute (since 1 kJ = 1000 J and 1 minute = 60 seconds).

Q4: How does travel speed affect heat input?
A: Faster travel speeds decrease heat input, while slower speeds increase it.

Q5: What about efficiency factors?
A: Some standards include an efficiency factor (η) in the formula (e.g., for SAW η=0.9). Add this if required by your specification.