Main Causes of Flange Deformation During Welding

Main Causes of Flange Deformation During Welding

1. Uneven Heat Distribution

• Welding introduces intense localized heat, causing thermal expansion in the weld zone.

• Uneven heating and rapid cooling create thermal stresses that lead to distortion or warping of the flange.

2. Residual Stresses

• As the weld metal solidifies and cools, it contracts, generating residual tensile and compressive stresses.

• These internal stresses can cause bending, twisting, or dimensional changes in the flange.

3. Improper Welding Sequence

• Incorrect weld sequencing or skipping balancing weld passes can cause uneven stress distribution.

• This leads to asymmetric deformation and misalignment of the flange.

4. Inadequate Fixturing or Clamping

• Lack of proper support or clamping during welding allows the flange to move or distort under thermal forces.

• Secure fixturing minimizes movement and controls deformation.

5. Welding Parameters and Technique

• Excessive heat input, high welding current, or slow travel speed increase heat concentration, aggravating deformation.

• Poor welding techniques such as improper bead size or incorrect joint preparation contribute to stress concentration.

6. Material Properties

• Different flange materials have varying thermal expansion coefficients and mechanical properties.

• Some materials are more prone to distortion under welding heat.

7. Thickness and Geometry of the Flange

• Thin or uneven thickness areas are more susceptible to warping.

• Complex flange shapes can create uneven heat distribution and stress concentration points.

Summary

Flange deformation during welding mainly results from uneven heat input, residual stresses, improper welding sequences, insufficient fixturing, welding technique, material properties, and flange geometry. Controlling these factors through proper welding procedures and support can effectively minimize deformation.