METHOD OF MEASURING ON-LINE HARDNESS OF STEEL PLATE.

摘要

This method comprises the steps of positioning a steel plate (21) and a DC-energized electromagnet (22) facing each other so that they are moving relative to each other, separately providing both the positive and negative poles of the magnet (22) in the direction of the relative movement, magnetizing to saturation part of the steel plate (21) which has been magnetized to saturation by one pole of the electromagnet (22) in the reverse direction by the other pole of the electromagnet (22), measuring the intensity of the residual magnetism of the part magnetized to saturation by a detector (24), and obtaining the hardness of that part from the intensity of the measured residual magnetism.