Welding distortion
Strenx® hot-rolled high-strength structural steel
In practice, for trailer applications, distortion due to welding is more critical than the static strength of the welds. Follow these tips to minimize the amount of distortion due to the welding operation:
- Weld with as low a heat input as possible
- Minimize the cross sectional area of the weld, as in the illustration below
- Prebend, clamp or angle the parts before welding in order to compensate for the shrinking
- Avoid irregular gaps in the root
- Use symmetrical welds, as in the illustration below
- Minimize reinforcements and optimize the throat thickness of the fillet welds
- Weld from rigid areas to loose ends
- Optimize the welding sequence
Cross-section of the weld and how it influences the angle deviation.
Use a symmetrical welding sequence.
To avoid a curved or deformed longitudinal beam after welding of the web, displace the web in relation to the center of the flange. This makes it possible to locate the longitudinal welds in the neutral layer of the flanges, as in the illustration below.
Displacing the web in relation to the flange makes it possible to weld in the neutral layer of the flange, which avoids deformations from welding.
Strenx® cold-rolled high-strength structural steel (CR)
In order to avoid heavy deformation of Strenx® CR steels, follow these guidelines:
- Weld with as a low heat input as possible.
- Use a wire with a small diameter (0.8 mm).
- Downhill welding technique reduces the heat input and is recommended if permitted by the application and the production conditions.
- If the application allows a small gap between the welds, intermittent welding can be used.
- If the application requires a sealed connection, silicon or adhesives could be used instead of welding to seal the connection and prevent corrosion to arise.
- Use lap welds instead of butt welds.
- Welding of thin sheets requires a short distance between the tack welds (80–120 mm).
- Power sources for MAG welding have greatly evolved, making it possible to weld thin sheets with approximately 50% lower heat input.
- If the joint is accessible from both sides, resistance spot welding can be used instead of fusion welding.
- Avoid welding and use mechanical joining, which ensures very low or no deformation.
The information in this report is only applicable to SSAB’s products and should not be applied to any other products than original SSAB products.
This report provides general results and recommendations for SSAB steel products. This report is subject to SSAB’s Terms of Use. It shall be the user's responsibility to verify that the information contained herein is correct and is suitable to be used for the particular purpose and application of the user. The report is intended to be used by professional users only who possess adequate expertise, qualification and knowledge for the safe and correct use of the results and recommendations in this report. This report is provided “as is”. The use of the report is at user’s own discretion and risk and that users will be solely responsible for any use of this report. SSAB disclaims any liability for the content or potential errors of this report, including but not limited to warranties and condition of merchantability or fitness for a particular purpose or suitability for individual applications. SSAB shall not be liable for any kind of direct or indirect damages and/or costs related to or arising therefrom, whether special, incidental, consequential or directly or indirectly related to the use of, or the inability to use, the report or the content, information or results included therein.