Case Study: The Need to Improve Specifications to Ensure Quality Control in Galvanized Steel

This paper presents a case study where the silicon content of the steel for a Structural Plate Corrugated Steel Pipe (SPCSP) was outside of specifications resulting in a product that developed defects in the galvanizing which mimicked a potentially serious problem. This paper describes the defect’s presentation, the investigation process, and illustrates how a single small defect can elude several levels of quality control inspections to cause a severe problem. Despite the various quality control inspections, the defect went undetected until the material had already been assembled into the final constructed product. It was found that existing specifications did not provide any guidance on the appearance of the galvanized surface and as such, the quality inspectors at each step of the quality control process had no indication to be concerned or any basis for rejection. It is proposed that existing specifications be modified to provide guidelines to address this issue.