Abstract： The brittle fracture of HRB400 hot rolled ribbed steel bar was inspected and analyzed by the means of chemical in-situ measurement, scanning electron microscopy (SEM) and metallographic structure examination. The results showed that the severe C and P segregation occurred in steel bar. Moreover, due to the rapid cooling rate after rolling in winter, many upper bainite structures with high strength and low plasticity were caused. There were some microcracks in local region of steel bar. In the case of bending, the stress concentration was formed at the cracks, which would expand rapidly. After repeated bending processing, the toughness of steel bar was reduced. These factors resulted in the brittle fracture of steel bar. On this basis, we put forward the corresponding improvement measures to the problem of brittle fracture of steel bar. The quality of HRB400 steel bar products had been improved, the brittle fracture phenomenon of steel bar did not occur in use.
徐雁，郭湛，王德宝，宋祖峰. HRB400热轧带肋钢筋脆断原因分析及改进[J]. 物理测试, 2022, 40(4): 49-53.
XU Yan，GUO Zhan，WANG Debao,SONG Zufeng. Cause analysis and improvement of brittle fracture #br# of HRB400 hot rolled ribbed steel bar. PHYSICS EXAMINATION AND TESTING, 2022, 40(4): 49-53.
2022, Vol. 40 
