Thermal Checking of Wrought-Steel Railway Wheel Material

Abstract

The mechanism of the formation of small cracks (thermal checks) that are formed as a result of two heat cycles is discussed. These thermal checks were noted in the treads of car wheels and careful examination of the conditions which caused them to form led to the development of a method of producing these thermal checks in a small specimen under better-controlled conditions. The reasons for the checks forming more readily in higher plain-carbon steel are discussed. Basically, the contraction of marten-site upon tempering seems to be the cause of the formation of thermal checks.