AT尖轨跟端锻压成型后采用电阻炉加热保温、三面喷风器完全喷风连续冷却快速正火工艺，通过控制冷却速度提升AT尖轨锻压段硬度、强度及韧性，使跟端锻压段性能均匀化。试验结果表明， AT尖轨跟端锻压段经正火喷风冷却工艺后表面硬度平均值340 HBW，最大波动值27 HBW，踏面第3点HRC硬度≥32.0，抗拉强度Rm≥1160 MPa，延伸率A≥12.5%，低倍腐蚀、金相组织及疲劳寿命均符合标准规定。建议对目前尖轨跟端锻压段正火后离线热处理工艺进行改进，利用正火温度进行在线喷风冷却工艺，提高了跟端性能均匀性，节约了能源、人工成本，提升尖轨的生产效率。%After the heel of AT switch rail is forged and shaped, resistance furnace is adopted to heat and keep warm. The process that jetting air by three-sides air jetter to cool continuously and normalizing quickly can improve the hardness, strength and toughness of heel forging area of AT switch rail and guarantee the uniformity of performance by controlling the cooling speed. Experimental results show that, after normalizing and cooling by jetting air, the average value of surface hardness of the heel forging area of AT switch rail is 340HBM, the biggest fluctuating value is 27HBW, HRC hardness of the third point on tread is larger and equal to 32.0, tensile strength Rm is larger and equal to 1 160 MPa, ductility A is larger and equal to 12.5 %. The low power corrosion, metallographic structure and fatigue life conform to the regulation. It is suggested that the process of off-line heating treatment after heel forging area of the switch rail is normalized should be improved, and the process of on-line cooling by jetting air through normalizing temperature should also be adopted. Thus the uniformity of heel area’s performance will be improved, the cost of energy and labor will be saved, and the productivity of switch rail will also be improved.
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