68kg/m钢轨的试验与评价

Test and Evaluation of 68kg/m Rail

针对国外重载铁路广泛使用68kg/m钢轨的情况,同时为满足我国发展重载铁路的需要,本文对68kg/m钢轨及其配套技术进行试验研究。按照北美标准,由国内钢厂轧制生产出热轧钢轨(抗拉强度为1 080 MPa)、在线热处理后抗拉强度为1 265MPa的68kg/m钢轨,通过厂内闪光焊、现场气压焊方法焊接成无缝线路,在京包上行线铺设15km试验段,其中半径1 200m以下曲线区段铺设在线热处理钢轨,其他区段铺设热轧钢轨,5年累计通过总重881 Mt·km/km,得到结论如下:在曲线区段,68kg/m在线热处理钢轨至下道时总的平均磨耗速率约为0.03mm/Mt,比60kg/m U75V热处理钢轨的耐磨性提高1倍以上;直线上累计通过总重881 Mt·km/km后,68kg/m热轧钢轨垂直磨耗约为2mm;累计通过总重881 Mt·km/km后,钢轨的重伤率为0.46处/km,远低于相同条件下60kg/m钢轨的重伤率;使用68kg/m钢轨的维修养护工作量比使用60kg/m钢轨减少约一半。综上,无论从技术性、配套性还是经济性上考虑,在我国铁路推广使用68kg/m钢轨是可行的。

In response to the situation where the 68 kg/m rail has been widely used on heavy haul railway all over the world , test and research were conducted on the 68 kg/m rail and its supporting technology in order to meet the development of heavy haul railway in China . The mechanical properties of the 68 kg/m rail produced in compliance with North American standard by domestic steel mills as follows ：As‐rolled ：Rm ≥1 080 MPa（for tangent track and R〉1 200 curves）;After heat treatment ：Rm ≥1 265 MPa（for R≤1 200 curves） . The 15 km test section had been established in Beijing‐Baotou railway with seamless rail made with flash butt welding and pressure welding . Over 881 million ton‐kilometers of freight has been moved by the 68 kg/m rail on this sec‐tion over the past five years . Findings from the research include：（1）The average wear rate of heat‐treated 68 kg/m rail was approximately 0.03 mm/Mt in R600~700 m curves ,which was half of the wear rate of heat‐treated 60 kg/m U75V rail . The vertical wear of the 68 kg/m as‐rolled rail was about 2 mm in tangent track af‐ter 881 million tons traffic . （2）The rate of serious damages was 0.46/km , which was much lower than the rate of serious damages of the 60 kg/m rail under the same conditions . （3）The track with 68 kg/m rail required about 50% less maintenance work than the 60 kg/m rail . To sum up , the widespread use of the 68 kg/m rail in the railw ays in China is feasible in terms of technical and economic considerations .