Influence of sample shape on high-intensity induction heated bend pipe in tensile test

Tensile performance is one of the important characteristics in high-grade pipe steel. Aiming at the high-grade X70 and X80 induction heated bend pipe steel, three shapes with different specifications are chosen to perform tensile test. Results obtained from the test show that different shapes affect the yield strength, tensile strength and yield ratio of the samples. For the transverse sample of X70 and X80 pipe steels, yield strength of the rectangular plant-like tensile sample is less than that of the round-bar tensile sample, but for the X70 longitudinal sample, the result is reversed. The tensile strengths for X70 and X80 pipe steels are almost the same between different sample shapes, the tensile strength of transverse-rectangular full wall thickness samples is just higher than that of columnar sample, and the yield ratio of transverse-rectangular full wall thickness X70 and X80 samples is less than that of columnar sample, and the yield ratio of longitudinal-rectangular full wall thickness X70 sample is higher than that of columnar sample. For the sake of steel pipeline operation safety, it is preferred to use the round bar sample for experiment.