RAILROAD RAIL HEAD REPAIR

摘要

A multi-pass gas metal arc weld (“GMAW”) approach is used for in-situ repair of railhead defects. A defect is removed via machining a perpendicular slot or grove in the railhead leaving the web and base unaltered. A sufficient number of GMAW passes are used to fill the slot using a weld material suitable for the particular type of parent steel, and excess weldment can be removed. Optionally, for pearlitic steel rails post-weld heat treatment can be used to cause austenization and/or quenching of the weld. The weld heat inputs and other parameters are controlled to avoid ductile and brittle fracture related morphologies.

主权项

1. A method for repairing railhead defects in a steel rail, comprising:
removing the railhead defect by forming a slot in a railhead of a steel rail, said slot removing defective material and some surrounding material, said slot being formed in a general perpendicular direction to the longitudinal direction of the rail; selecting a welding material having physical properties closely correlating with those of the steel rail; using said welding material to fill the slot by multi-pass gas metal arc welding (“GMAW”) at a heat input that is sufficiently high to avoid ductile fracture characteristics and sufficiently low to avoid brittle fracture characteristics, wherein a sufficient number of passes of said GMAW is performed until said slot is completely filled by a weld formed from said welding material; removing any excess welding material extending out of said slot so as to form a substantially continuous repaired railhead surface.