Method and device for detecting depth of hardness layer of TBM (Tunnel Boring Machine) cutter box plate

The invention relates to the field of cutter box plate performance testing, and provides a TBM cutter box plate hardness layer depth detection method, which comprises the following steps: feeding a TBM cutter box plate into a heating furnace, heating to a specified temperature, carrying out heat preservation after heating, taking out the TBM cutter box plate from the heating furnace, feeding the TBM cutter box plate into a quenching area, quenching until the TBM cutter box plate is completely cooled, and then taking out the cooled TBM cutter box plate; the cooled TBM cutter box plate is cut and sampled, and the two side faces of the quenching face of the sample are ground to be flat and shiny; repeatedly wiping the ground planes on the two sides of the sample with alcohol, then dipping a cotton swab in a 4% nitric acid corrosive liquid to repeatedly wipe the ground planes, standing and waiting, and enabling the surface of the sample wiped by the 4% nitric acid corrosive liquid to have obvious color change. Th