Welding quality control method for ERW steel pipe

ERW steel pipes use electric resistance welding technology, making the control of welding quality a critical aspect of the manufacturing process. Ensuring high-quality welds involves a series of thorough inspections and procedures. Here’s an overview of the methods used for controlling the welding quality of ERW steel pipes.

1. Destructive Inspection Procedures

Destructive inspection involves separating the welded joint to examine its quality. A tool or device is inserted between the weld and the adjacent section until the components are completely separated. The weld diameter is measured in two perpendicular directions, with the smaller measurement being recorded. For welds involving multiple components, each pair of adjacent components must be inspected.

a. Process Setup Phase: During initial setup, perform destructive inspections at each sub-assembly station to verify weld quality and identify potential weak points.

b. Inspection of Suspicious Areas: Continue destructive inspections in any areas where weld quality is suspect until all welds meet the required standards.

c. Pilot Production Stage: Conduct comprehensive destructive inspections of welds in all assembly areas to ensure quality under normal production conditions. Re-inspect suspicious areas during pre-production to confirm they meet process requirements.

d. Full Production Stage: Perform regular destructive inspections on-site, following a scheduled inspection cycle. Include sub-assemblies in the inspections to ensure all welds are thoroughly checked.

e. Ongoing Analysis: Continuously analyze the results of inspections and focus on inspecting potentially problematic welds until they are fully controlled and corrective measures are effectively implemented.

f. Quality Assurance Audit: Destructive inspections serve as an audit of the overall welding quality assurance system. If defective welds are found, immediately identify and isolate all affected workpieces until appropriate corrective actions are taken.

2. Routine Inspection Methods

Operators should employ the following inspection methods to verify the number and location of welds and ensure continuous monitoring of weld quality. The quality department should be notified if any welds appear questionable.

a. Visual Inspections: Regularly check welds for visible defects and adherence to specifications.

b. Non-Destructive Testing (NDT): Use techniques such as ultrasonic testing, radiographic testing, or magnetic particle inspection to detect internal flaws without damaging the welds.

c. Dimensional Checks: Measure weld dimensions to ensure they comply with specified criteria.

e. Reporting and Documentation: Document inspection results and report any issues to the quality department for further investigation and action.

By adhering to these rigorous inspection procedures, manufacturers can ensure that the welding quality of ERW pipes meets industry standards, resulting in reliable and durable products.