• CN:11-2187/TH
  • ISSN:0577-6686

›› 2011, Vol. 47 ›› Issue (16): 20-24.

• 论文 • 上一篇    下一篇

高锰钢辙叉机械冲击预硬化工艺研究

杨志南;张福成;张明;刘峰超;孙登月   

  1. 燕山大学亚稳材料制备技术与科学国家重点实验室
  • 发布日期:2011-08-20

Study on Mechanical Impact Pre-hardening Technology of High Manganese Steel Crossing

YANG Zhinan;ZHANG Fucheng;ZHANG Ming;LIU Fengchao;SUN Dengyue   

  1. State Key Laboratory of Metastable Materials Science and Technology, Yanshan University
  • Published:2011-08-20

摘要: 为提高高锰钢辙叉的耐磨性能和抗变形能力,利用自制的机械冲击预硬化设备对高锰钢辙叉表面进行预硬化处理。适合高锰钢辙叉服役条件的最佳机械冲击硬化工艺如下所述,将高锰钢辙叉待硬化表面加热到300 ℃,利用冲击能量为50 J的机械装置冲击辙叉工作面,每个硬化点冲击时间大于10 s,相邻硬化点边缘距离小于3 mm。高锰钢辙叉经过机械冲击硬化处理后获得硬化层深度大于15 mm、表层硬度约为48 HRC、亚表层硬度梯度平缓过渡的理想硬化效果。亚表层硬度梯度平缓过渡是由于高锰钢辙叉被加热到300 ℃后,屈服强度降低,机械冲击后塑性变形区厚度增加所致。同时,在300 ℃冲击变形过程中高锰钢微观组织发生动态回复,降低了辙叉表层硬度,使硬化效果更适合铁路辙叉服役。高锰钢辙叉经过机械冲击硬化处理后使用寿命明显提高。

关键词: 高锰钢辙叉, 机械冲击, 预硬化

Abstract: In order to increase the wear resistance and the deformation resistance of high manganese steel crossing, mechanical impact pre-hardening is carried out on the work surface of high manganese steel crossing. The mechanical impact hardening process optimized for high manganese steel crossing service is as follows: heating the surface of high manganese steel crossing to 300 ℃, and then using a self-made device to impact the surface of high manganese steel crossing. Each hardened point is impacted for ≥ 10 s, and the edge distance of each hardened point is ≤ 3 mm. The hardened depth of high manganese steel crossing is more than 15 mm after the mechanical impact hardening with the surface hardness of 48 HRC. The decreasing of hardness from surface to interior is gentle which results from the decrease of yield strength after the high manganese steel crossing is heated to 300 ℃, and the increase of thickness of the plastic deformation region after the mechanical impact. At the same time, because dynamic recovery occurs in microstructure of high manganese steel during the process of impact deformation at 300 ℃, the surface hardness of the crossing is decreased, so that the hardening result is more suitable for the service conditions of railway crossings. The service lifetime of the high manganese steel crossing is obviously improved after the mechanical impact hardening.

Key words: High manganese steel crossing, Mechanical impact, Pre-hardening

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