Reasons Analysis on Fracture of Q235B Steel Fire Spray Pipeline on Crude Oil Tank

The frequent cracking reasons of Q235B steel fire spray pipeline on crude oil tank were analyzed through macroscopic observation, mechanical properties test, metallographic examination, scanning electron microscopy observation and energy spectrum analysis. The results show that the main reason for lamellar cracking of the fire spray pipeline was the large numbers of silicate non-metallic inclusions which distributed in the form of layers beside the weld.