Study on High-frequency Welding Conditions for CT80 Coiled Tubings

Evaluations of the weld joint specimens of the Φ38.1 mm×3.18 mm CT80 hi-frequency welded coiled tubings as made with different welding conditions are conducted based on the results of the macrostructure and microstructure metallographic analyses and the flattening test. Also summarized are the quality levels and characteristics of the flattening test specimen fractures of the coiled tubings as produced under different welding conditions, resulting in the basis for evaluating the rationality of the welding conditions, and for establishing proper welding conditions as well.