The reasons for making body crack defects are analyzed in actual production by using quality administrative methods,put forward some solving methods,and they are proved very effective in practice.

To solve the problems of the rail fracture during straightening,bloom fracture and over-firing that occured at the beginning of commercial production of high carbon microvanadium PD_3 steel rail recently developed by Pangang,macroscopic observation and metallographic study are used to analyze the main mechanisrns for the material failure.