Question

Autogenous gas tungsten arc welding of a steel plate is carried out with a welding current of $500A$. Voltage of $20V$ and weld speed of $20mm/mn$. Consider the heat transfer efficiency from the arc to the weld pool as $90$%. The heat input per unit length (in $KJ/mm$) is

• A. $55$
• B. $27$
• C. $35$
• D. $45$

Answer 1

The correct option is B $27$

$\text{Heat input}=\eta \frac{VI}{v}=\frac{0.9\times 20\times 500\times 60}{20}$

$=27000J/mm\text{or}27kJ/mm$