Abstract

High-frequency electric resistance welding (HFERW) is one of the most common process for production of longitudinal welded carbon steel pipes, suitable for line pipes, casing, and tubing. In the edges joining line of hot rolled coils is formed decarburization layer which sometimes appeared negative impact on the microstructure and mechanical properties of the welded joint, so the aim of this paper is to investigate impact of this layer on the crack propagation in the pipes welded joint, obtained by high frequency electric resistance welding (HFERW). Crack propagation in the pipes welded joint monitored by macro and microscopic analysis as well as by the hardness testing, along and transverse through decarburization layer. Results of this investigation brings additional knowledge about impact of the decarburization layer on the crack propagation in the high frequency electric resistance welded joint.