Calculate Welding Heat Input per Point

In summary,A welder is using a 110A current and a 20V welding voltage to weld two pieces of metal. 100% of the electric energy is converted to heat, resulting in 2.2KJ/sec of heat input. The length of the pieces being welded is 2 meters, and to calculate the heat input at each point, the welder needs to know the welding speed and the power generated. If the welder welds faster, then the heat input will be less, resulting in a less stressed weld.
  • #1
chandran
139
1
In a welding process,i am welding two plates. The welding current is 110A and welding voltage is 20V. Suppose 100% of this electric energy is
converted to heat then the heat energy generated is 110x20. i.e., 2.2KJ/sec.
Suppose the length of the plate is 2 metres, How can i calculate what is the heat input into the welded joint at each point? I have one more data
that welding speed is 1metre/minute.
 
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  • #2
(assuming no losses) power generated / welding speed = heat input per unit length
 
  • #3
if the welder weld faster then heat will be less thereby producing a good
less,residual stress weld?
 
  • #4
chandran said:
if the welder weld faster then heat will be less thereby producing a good
less,residual stress weld?
Perhaps. Any weld is going to create stresses. The increased speed would have to be balanced by the fact that a certain percentage of the weld penetration would be sacrificed. Most welds are stress relieved after the process.
 
  • #5
Yeah, if you require the weld to penetrate (well, you usually do) I think you can't really gain much residual stress wise by decreasing heat input (material properties are a different matter of course). Typically heat input affects the residual stress gradient at line of fusion towards the base material, where there is a square root dependency between the yielded zone and arc power, which again has a linear relationship with the extension of the residual stress field - but this leaves the weld metal residual stresses still as is, higher arc powers widen the volume under residual stresses. Would go with post-weld heat treatment.
 
  • #6
Power beam welding processes (e-beam, laser welding) tend to be better in applications where residual stress is a concern. The power density is much higher, although the net heat input is often lower than electric arc welding techniques. As a result, the heat affected zone tends to be a lot smaller. (Pretty much what Perennial said...). I don't think a simple increase of welding speed is going to solve any problems.
 
  • #7
Hello, How to input heat source in welding simulation ( ANSYS ).By heat flux or heat genaration or heat flow etc...?.How to calculate if effic=60%,V=16, I=80,weld speed=1 m/min.
 
Last edited:

1. What is welding heat input per point?

Welding heat input per point is a measure of the amount of heat energy being applied to a specific point during the welding process. It is typically measured in Joules per millimeter (J/mm) and is an important factor in controlling the quality of a weld.

2. Why is it important to calculate welding heat input per point?

Calculating welding heat input per point is important because it helps ensure that the weld is not overheated, which can lead to defects such as cracks or distortions. It also helps determine the appropriate welding parameters and can be used to monitor the quality and consistency of the welding process.

3. How is welding heat input per point calculated?

Welding heat input per point is calculated by multiplying the welding voltage by the welding current and the welding speed. This value is then divided by the cross-sectional area of the weld. The resulting unit is J/mm.

4. What factors can affect the welding heat input per point?

The welding heat input per point can be affected by several factors, such as the type of welding process, the welding parameters (voltage, current, speed), the material being welded, and the joint design. It is important to carefully control these variables to ensure that the welding heat input per point is within the appropriate range for the specific application.

5. What is the recommended range for welding heat input per point?

The recommended range for welding heat input per point varies depending on the welding process and the material being welded. In general, it is recommended to stay within 1-2 kJ/mm for most welding processes. However, it is important to consult specific welding codes and standards for the recommended range for a particular application.

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