Effect of Online Slacking-Quench on the Microstructure and Properties of U75V Rail
LI Bo1， ZHU Guo-ming1， TAO Gong-ming2， KANG Yong-lin1
（1. School of Materials Science and Engineering， University of Science and Technology Beijing， Beijing 100083， China 2. Pangang Group Panzhihua Steel and Vanadium Co.， Ltd.， Panzhihua 617000， Sichuan, China）
Abstract：In order to further get the effects and mechanisms of the online slacking-quench on microstructures and mechanical properties of U75V rail, the microstructures of the whole section of the hot rolled and slacking-quench on line rail was observed using scanning electronic microscope, and the effect of on-line slacking-quench on the mechanical properties of U75V rail was compared and analyzed using Vicker’s indentation test machine and tensile testing machine. The results show that the microstructure of the whole section of the rail was lamellae pearlite in both on-line slacking-quench and hot rolling; but the pearlite interlamellar spacing after online slacking-quench was distinctly refined. The pearlite interlamellar spacing of the hot rolled rail was about 0.113 μm to 0.284 μm, while that of the slacking-quench rail was about 0.076 μm to 0.148 μm. The microhardness of the whole section of the hot rolled rail had little difference, while the slacking-quench rail microhardness was much higher. Moreover, the mechanical properties of U75V rail had been improved effectively by on-line slacking-quench; and the rail tensile strength and elongation increased by 16.6% and 20% compared that of hot-rolled rail, respectively.
李 波， 朱国明， 陶功明， 康永林. 在线余热淬火对U75V钢轨组织性能的影响[J]. 钢铁, 2014, 49(7): 101-106.
LI Bo， ZHU Guo-ming， TAO Gong-ming， KANG Yong-lin. Effect of Online Slacking-Quench on the Microstructure and Properties of U75V Rail. Iron and Steel, 2014, 49(7): 101-106.
2014, Vol. 49 
