1. What is a Heat Input Calculator?

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

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

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( HI \) — Heat Input (Joules per inch)
• \( V \) — Voltage (volts)
• \( I \) — Current (amps)
• \( S \) — Travel Speed (inches per minute)

Explanation: The formula calculates the energy transferred per unit length of weld by accounting for electrical power (V×I) and the speed at which the weld is made.

3. Importance of Heat Input Calculation

Details: Proper heat input control ensures adequate penetration, reduces defects, and maintains mechanical properties of the welded joint.

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, microstructure, and mechanical properties. Too high can cause brittleness, too low can cause lack of fusion.

Q2: What are typical heat input ranges?
A: Typically 20-60 kJ/inch for most processes, but varies by material and process (e.g., 15-30 for stainless steel, 20-45 for carbon steel).

Q3: Why is travel speed in the denominator?
A: Faster travel speeds reduce heat input because the energy is distributed over more length of weld per minute.

Q4: What's the purpose of the 60 multiplier?
A: It converts minutes to seconds since joules are watt-seconds (1 watt = 1 joule/second).

Q5: Does this work for all welding processes?
A: Yes, for arc welding processes (SMAW, GTAW, GMAW, FCAW, SAW) but may need adjustment for resistance or laser welding.