Method of forming plate-type track shoe

Abstract

A method of manufacturing a plate-type track shoe. The method involves casting or obtaining a cast, plate-type track shoe which has been made from a suitably high quality ductile iron and heating the plate-type track shoe to a desired austentizing temperature within a range of about 1450.degree. F.-1750.degree. F. for up to about six hours to austentize the ductile iron. The plate-type track shoe is then rapidly cooled to a desired austempering temperature within a range of about 450.degree. F.-800.degree. F. and maintained at the desired austempering temperature for up to about 6 hours to isothermally produce a plate-type track shoe having an ausferrite microstructure. The plate-type track shoe is then cooled, washed, and optionally coated with a rust inhibitor and/or coated or painted. The process produces austempered plate-type track shoes which have high strength, excellent durability, and which are less costly to produce, per pound, than comparable parts manufactured from formed steel. Additionally, the cast feature allows surface features and indicia to be incorporated which is not possible with roll formed steel track plates. Most importantly, the process of the present invention enables specific, desired quantities of track shoes to be produced, which would not be possible with parts formed from steel, where an entire heat of rolled steel would have to be purchased and used, thus requiring the manufacture and inventorying of a very large quantity of track shoes.

Dependencies are inferred from the claim text.