After working on line six months or so,the 115RE rail has 220 mm-length longitudinal crack in waist. By macro-analysis to the 糖心产精国品免费入口*完整版rail,micro-analysis the sampling from crack source region by the stereoscan and the metalloscope,and checking the related mechanical property,the results indicates that the rail’s material is normal in quality,and the cracks occur from the bigger 糖心产精国品免费入口*完整版 in the bottom of rail-waist’s batch number “2” letter trace.