PRODUCTION METHOD THAT REDUCES RESIDUAL STRESS OF HEAT-TREATED STEEL RAIL AND RESULTING STEEL RAIL

• Main Authors: ZHU, Min, YE, Jialin, DONG, Maosong, WANG, Ruimin, ZHOU, Jianhua, WANG, Jun, FEI, Junjie, ZHENG, Jianguo
• Format: Patent
• Language: Chinese; English; French
• Published: 01.04.2021
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

A production method that reduces the residual stress of a heat-treated steel rail, and the resulting steel rail. The method comprises: carrying out on-line accelerated cooling treatment on a hot rolled steel rail, where the starting cooling temperature is 700-880°C, the cooling speed of a rail head is 5-8°C/s, the cooling speed of a rail bottom is 1.5-3°C/s, and cooling to reduce the temperature of the rail head to 460-550°C; carrying out slow cooling treatment at a slow cooling speed of 0.5-1°C/s, until the temperature of the rail head is reduced to 350-450°C; and keeping the cooling speed of the rail head as 0.5-1 °C/s, controlling the cooling speed of the rail bottom at 0.5-2°C/s, and when a temperature difference of the rail head and the rail bottom reaches a certain range, stopping accelerated cooling and carrying out natural cooling to room temperature. The production method may effectively reduce the residual stress of the rail bottom of the steel rail, and improve the service life of the steel rail an