Edge Quality and Its Impact on Welding in Cut-to-Size Steel Plates

Edge quality is one of the most critical factors affecting the welding performance of cut-to-size steel plates. Whether the plates are processed by laser cutting, plasma cutting, oxy-fuel cutting, or waterjet cutting, the condition of the cut edge directly influences weld penetration, joint strength, and fabrication efficiency. Manufacturers in pressure vessel, shipbuilding, bridge construction, and heavy equipment industries increasingly prioritize high-quality cut edges to reduce welding defects and production costs.
A high-quality edge is characterized by minimal burrs, low surface roughness, accurate dimensions, and a narrow or nonexistent heat-affected zone (HAZ). These characteristics improve weld fit-up, reduce filler metal consumption, and ensure uniform heat distribution during welding. In contrast, rough edges or excessive slag often require additional grinding, increasing labor costs and production time.
Experimental comparisons conducted on 25 mm ASTM A36 steel plates revealed significant differences between cutting methods. Laser-cut specimens achieved an average edge roughness of Ra 2.8–3.5 μm, while plasma-cut edges measured Ra 8.0–10.5 μm with a heat-affected zone of approximately 1.5 mm. During MAG welding tests, laser-cut joints showed 98.6% weld penetration consistency, whereas plasma-cut samples experienced nearly 12% more porosity due to residual oxides and uneven edge geometry.
Edge quality also affects mechanical performance after welding. Tensile testing of welded S355 structural steel plates demonstrated that specimens with precision-machined or laser-cut edges reached an average tensile strength of 552 MPa, while poorly prepared edges reduced joint strength by approximately 6–8%. Fatigue testing further indicated that smoother weld toes and cleaner edge preparation increased fatigue life by nearly 20%, making edge quality especially important for dynamically loaded structures such as cranes, bridges, and offshore platforms.
To achieve optimal welding performance, manufacturers should select cutting technologies based on plate thickness, steel grade, and fabrication requirements. Combining precision cutting with proper edge cleaning and welding procedures minimizes defects, improves structural reliability, and enhances overall manufacturing efficiency.