3. Influence of rail chemical composition

The influence of chemical composition on the TRC (continuous cooling transformation) curve was described in the article "Rails de chemins de fer. Aspects métallurgiques" [M 3 070] the influence of chemical composition on the TRC (continuous cooling transformation) curve, which defines the cooling rate to be adopted in order to obtain a pearlitic structure without any trace of martensite.

Some high-alloy grades may require heavy-duty postheating after welding to reduce the cooling rate, which has the disadvantage of enlarging the heat-affected zone (HAZ).