ERW Straight Welded Pipe Weld Shape

Welding process of erw steel pipe is the use of the skin effect of high frequency current generated by the principle of hot rolled coil edge heated to a molten state, and then by mechanical extrusion welding method. Produced by this process is indeed welded steel weld fusion centers have a white line in the heat affected zone on both sides of the fusion line extending from the middle will have to face the direction of metal flow lines. During the welding process, the metal tube through the cold, hot, then cold thermal cycling process, therefore, physical and chemical properties of the base material, grain size, non-metallic inclusions, forming and welding conditions and heat treatment process, and this will impact on the performance of the weld toughness especially red. In pipe production process, through the selection of impact toughness of steel coils to ensure the performance of welded steel base metal, combined control and adjustment of the welding process to ensure as much as possible to reduce defects, guarantees high weld performance. Weld quality weld seam appearance that can weld morphology, and mechanical properties of the weld surface condition detection and metallurgical analysis to determine. In the production process, the weld curved shape and the surface condition of the welding process can provide a reference for the adjustment. Mechanical properties testing generally in accordance with the standards or user-specific requirements. Inconsistencies within and outside edge of the board can not exceed the temperature range, otherwise it will have serious quality problems. The more typical problem is the two extremes burnt and cold welding. Burnt is to ensure that all of the inside and outside, "penetration", resulting in high temperature side of the "burnt." After removing burrs can be found oxides and impurities just stay in the side, not visible to the naked eye formation welding cracks or holes. Degree by flattening slightly lighter to check out. Or to limit the scope of the outside temperature exceeds a certain cause other side appeared cold welding. When the temperature difference is not completely outside the above range, the welding must be judged by the quality inspection. Whether heating the slab edge unanimously by the observation of the outside bead size burrs or projections are consistent can be. Generally indicates the outer edge of the outer coarse protrusions on the inner edge of the heating intensity, whereas the inner edge of the high temperature. Whether it appropriate ultimately affect the quality of the weld strength and weld joints between exterior extrusion amount of a heating temperature. Typically the welding process, the following occurs: When asked appearance quality, often appear soldering temperature is too low; weld strength when stressed, usually occurs soldering temperature is too high; or proper welding temperature, extrusion volume control improper. In general, the amount of the extrusion can have a proper range, when a large amount of extrusion, due to lower the heating temperature; when the pressing amount is small, a suitable heating temperature, which ensures that the weld strength and weld forms to achieve a better The combined effect.