Troubleshooting Weld Integrity in Cold Rolled Tube Production

Over the years, Roll-Kraft has conducted thousands of mill evaluations on a variety of equipment. We are now sharing these stories in our Tube & Pipe Field Service Report Article Series. We hope you find the information contained in this series helpful. If you have any questions regarding your mill, use our contact form to request more information about our on-site mill evaluation.

Problem: 
A tube and pipe producer was experiencing persistent issues with weld integrity and surface marking during the production of 2" x .035" wall cold rolled brite tubing. These defects not only affected product quality but also increased scrap rates and reduced customer satisfaction.

Challenge: 
Upon investigation, it was determined that the incoming strip width for the .035" wall product was narrower than required. The .035" wall product was being supplied at a strip width of 6.290", approximately .035" narrower than theoretical strip width of 6.324”. This discrepancy made it difficult to form the tube properly through the breakdown and fin pass sections of the mill, particularly impairing edge preparation for welding. The result was inconsistent seam formation, which compromised weld quality.

Solution: 
To address the immediate production needs, the technician devised a revised set of fin pass dimensions/measurements, tailoring each pass to better accommodate the narrower strip width. Adjustments were also made to the weld roll pressure settings, improving the size and consistency of the weld bead while minimizing marking on the tube surface. Test samples were taken and subjected to destructive and metallurgical analysis, which confirmed that the weld integrity had improved significantly. As a long-term solution, a formal change order was initiated to procure strip at the correct width of 6.324" for future runs. This proactive approach ensures that forming and welding processes can operate within design and setup parameters, reducing rework and enhancing product quality.

Contact Roll-Kraft for a Tube & Pipe Mill Evaluation
Do you have issues you would like a second opinion on regarding your mill? Roll-Kraft on-site evaluations really make an impression with your staff, confirming you are serious about producing quality tube, pipe, and roll form products. Our technicians will tell you exactly where you are currently doing a great job, in addition to pointing out any areas that could be improved. We have been doing training and evaluations for over 30 years and understand the sensitive nature of bringing someone in to talk about improvements. Your staff will be in good hands with Roll-Kraft. Click here to learn more about our tube & pipe evaluation service.