Test Study Of 75N-PG5 Rail Application Performance Under Heavy Haulage Condition

With the continuous improvement of the train's axle weight,speed and running density,the damage such as rail side grinding and stripping falling is getting more and more serious,In particular,the rail disease of small radius curve and rail welding quality are the key to the safety of heavy load transportation.Existing research showed that the abrasion and stripping drop of the rail are directly related to the strength and hardness of the rail,this paper is based on Shuohuang railway which has a typical heavy load transportation mode and study the trial application of a new type of high strength eutectoid steel rail 75N-PG5(U95Cr)on the curve of small radius of heavy load.By analyzing the rail's chemical composition,performance and welding quality,measuring flatness and hardness of welded joint,tracking and observating the surface state,the change of base material hardness,the development trend of wear of PG5 rail paved on Shuohuang railway,at the same time comparing the historical application of PG4 rail,the results of the study are as following:(1)Experimental research showed that all the performance indexes of PG5 rail meet the specifications for the use of steel rails with small radius curves for heavy duty railways;In the small radius concentration section of Shuohuang railway,it had been in service for 1.5 years without any flaw detection alarm,the weight meet 500 million tons by total and the performance of aluminum hot welding joint was stable;(2)Comparison with the mature PG4 rail in China at present,both the tensile strength and the tread hardness of the rail head of PG5 are higher than that of the PG4 rail,and the wear resistance was 17.84% higher than PG4 rail.The PG5 rail welding joint had stable performance,and its comprehensive performance was better than PG4.(3)The heavy duty small radius curve can use high strength rail,and extend the service life of the rail by supporting the later grinding and curing.It can pre-polish before passing a total weight of 30 Mt,have preventative grind before passing a total weight of 30 Mt to 80 Mt and reparable grind before passing a total weight of 120 Mt.