Interrupted normalization heat treatment process

A process for normalizing large section, large mass ferritic alloy steel workpieces that includes the steps of rapidly cooling at least outer surfaces of a workpiece from a temperature above the Ac.sub.3 temperature to a temperature below the Ar.sub.1 temperature and forming bainitic structures in the outer surfaces and during subsequent air cooling to room temperature reheating the outer surfaces of the workpiece to a temperature at least above the Ar.sub.1 temperature with bleed back heat from the workpiece and retaining as many bainitic structures as possible at the outer surfaces, thereby forming an alloy steel with outer surfaces and predominately bainitic structures.

A process for normalizing a ferritic alloy steel that includes the steps of rapidly cooling at least outer surfaces of the steel from a temperature above the Ac.sub.3 temperature to a temperature below the Ar.sub.1 temperature and forming bainitic structures in the outer surfaces and during subsequent air cooling to room temperature reheating the outer surfaces of the steel to a temperature at least above the Ar.sub.1 temperature with bleed back heat from the steel, thereby forming an alloy steel having predominately bainitic structures.

A process for normalizing large section large mass ferritic alloy steel workpieces that includes the steps of rapidly cooling at least outer surfaces of a workpiece from a temperature above the Ac.sub.3 temperature to a temperature below the Ar.sub.1 temperature and forming bainitic structures in the outer surfaces and during subsequent air cooling to room temperature reheating the outer surfaces of the workpiece to temperature at least above the Ar.sub.1 temperature with bleed back heat from the workpiece, and forming an as normalized workpiece having predominately bainitic structures.