Magnetic Barkhausen technique has been used to parametrically image the effects of thermal exposure on the surface condition of industrial components. Wear and fatigue resistance of industrial components are primarily determined by the mechanical condition of the surface layer. Standard hardness measurement techniques cannot easily be used to assess the condition of components in service because they are not well adapted to in situ measurements and are essentially destructive in nature. Barkhausen signals are sensitive to changes in surface hardness because the altered microstructure affects the dynamics of domain wall motion and consequently the Barkhausen signal. This paper presents the results of Barkhausen technique used to image the surface hardness on a flat plate material.