Abstract:

Different batches of multidiameter shafts used for rail truck, produced by 0Cr16Ni5Mo in a factory, were tested, analyzed and researched by many testing techniques. They were chemical composition analysis, mechanics performance testing, ultrasonic flaw detection, microstructure observation, areascan of elements and energy dispersive spectrometer analysis. The results showed that the products smelted in a dualprocess and forged in different stage could meet technical requirement. The smelting process was smelting in vacuum induction furnace and electroslag remelting. Diameter of the electrode bar was 330 mm and diameter of the steel ingot smelted was 610 mm. Some conclusions were drawn in this paper. One was that the accurate control on chemical component of the electrode bar could be achieved by setting correct parameters on the frequentness of whisking and temperature in refining period. The other was that the gaseous oxygen content also reduced from 66×10^-6 to 30×10^-6. Besides, detailed optimized parameters of Multidiameter shaft produced by 0Cr16Ni5Mo in the process were determined. The smelting frequency was 150 Hz. The whisking rate of flow with gaseous Ar was 70～80 L/min and the whisking frequency 65 Hz. The temperature of the homogenized diffusion process was 1 150 ℃ for 3 h and 1 050 ℃ for 5 h. The tonnage in the stage of upsetting and molding were 3 500 and 2 000 respectively.

Key words: Multi-diameter shaft, Flaw detection, Microstructure, Dual-process, Fast forgiing

摘要： 采用超声波探伤、组织观察、元素面扫和能谱测试手段,对某厂最新研制的铁道车辆用0Cr16Ni5Mo阶梯轴不同批次产品进行分析和研究,确定在真空感应炉冶炼电极棒Φ330mm-电渣重熔Φ610mm 钢锭双联工艺下冶炼,再经阶段锻造,其产品可达技术要求。合理设置真空感应炉精炼期搅拌频度和温度,不仅可以实现对电极棒化学成分的精准控制,而且可以使气体中氧气质量分数由66×10^-6降至30×10^-6。研究表明,0Cr16Ni5Mo阶梯轴生产工艺优化条件为:冶炼频率为150Hz,Ar气搅拌流量为70~80L/min,搅拌频率为65Hz,在1150、1050℃的温度下分别均质化处理3h和5h,阶段快锻在3500t的条件下进行镦粗处理,在2000t的条件下成材。

关键词: 阶梯轴, 探伤, 显微组织, 双联工艺, 快锻