针对国外重载铁路广泛使用68 kg／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68 kg／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1080 M Pa）、在线热处理后抗拉强度为1265 M Pa的68 kg／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15 km试验段，其中半径1200 m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 M t・km／km ，得到结论如下：在曲线区段，68 kg／m在线热处理钢轨至下道时总的平均磨耗速率约为0.03 mm／Mt ，比60 kg／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 M t・km／km后，68 kg／m热轧钢轨垂直磨耗约为2 mm ；累计通过总重881 M t・km／km后，钢轨的重伤率为0.46处／km ，远低于相同条件下60 kg／m钢轨的重伤率；使用68 kg／m钢轨的维修养护工作量比使用60 kg／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68 kg／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 .
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