Objective To investigate the influence rules of fluoboric acid (HBF4) on corrosion behaviors of 1Cr18Ni9Ti austenitic stainless steel, and provide corrosion evidences for the industrial acid descaling. Methods The effect of fluoboric acid on corrosion behaviours of 1Cr18Ni9Ti austenitic stainless steel was studied by means of rotary weight-loss test and metallographic microscope and scanning electron microscope observation. Meanwhile, its performance of scale-removing was also evaluated. Results Hydrofluoric acid, hydrolysate of fluoboric acid, dissolved the passive film on the stainless steel surface and caused serious corrosion on the metal surface. The results by means of metallographic microscope, SEM and EDS showed that the destructive form of metal was mainly unevenly distributed general corrosion, with evident pitting characteristics. The corrosion rate of metal tended to reduce and stabilize with immersion time. Besides, the increase of temperature and flow rate would accelerate corrosion velocity. But there was a significantly linear relationship between flow rate and corrosion velocity. Scale removal experiments showed that a good removal of carbonate scale could be obtained by fluoboric acid, and the scale removal rate could reach more than 97%. Conclusion When fluoboric acid is selected to remove scale, only strictly controlling technical parameters could reduce the bad corrosion to the metal substrate and prolong the service life of equipment.