MANUFACTURE OF RAIL WITH SUPERIOR EDGE BREAKING RESISTANCE

摘要

PURPOSE:To obtain a rail with improved edge breaking resistance by rapidly cooling the head of the connected part of a rail and the body close to joint holes after finishing hot rolling at a specified temp. to provide compressive residual stress to the connected part. CONSTITUTION:The head 1 of the connected part of a rail and/or the body 3 close to joint holes 6 is rapidly cooled by spraying a refrigerant such as water after finishing hot rolling at 400 deg.C - a temp. just below the A1 transformation point or carrying out heating to said temp. By this method large compressive residual stress is provided to the connected part of the rail to extend the fatigue limit, so the edge breaking resistance of the rail is improved, and the endurance life is prolonged.