Causes Analysis on Bending Fracture of HRB400 Hot Rolled Ribbed Bars

HRB400 hot rolled ribbed bar is one of the commonly used steels in construction industry. The HRB400 hot rolled ribbed bars of an iron and steel plant fractured when they were bended at the job site, and the bending fracture reasons were analyzed by means of chemical compositions analysis, metallographic examination, fracture SEM analysis, tensile test and bending test. The results show that bending diameter being too small and martensite abnormal microstructure caused by composition segregation, were two main causes for the bending fracture of the HRB400 hot rolled ribbed bars.