A formula is proposed to calculate the chemical austenitising temperature derived by means of a neural network model. A wide range of compositions were used, allowing to predict changes of tendency in the slopes of the austenitisation temperature, consistent with the existence of a eutectoid composition.Spanish Comision Interministerial de Ciencia y Tecnologıa (CICYT) (project-MAT 2001-1617). Spanish Ministerio de Ciencia y Tecnologıa for the financial support in the form of a Ram´on y Cajal contract (Programa RyC 2002). The authors also are grateful to Dr. Thomas Sourmail for the provision of the neural network software used in this work.Peer reviewed