Automatic detection device for depth of induction heat-treatment hardened layer on inner surface of steel pipe

The invention relates to an automatic detection device for the depth of an induction heat-treatment hardened layer on the inner surface of a steel pipe. The automatic detection device comprises a detection head part, a detection sleeve rod, a sleeve rod bracket base, a pipe transport trolley, a detection platform, a pneumatic device, a coupling agent water circulation system, an electronic controlcabinet and a multi-layer sleeved closed tube; the detection head part is internally provided with a pneumatic conical wedge, multiple movable side rods with ultrasonic probes are evenly distributedon the circumference of the pneumatic conical wedge, the detection sleeve rod is used for introducing power, gas and coupling agent water to the detection head part, and the multi-layer sleeved closedtube is internally provided with a water channel, a gas channel and a cable channel separately. The automatic detection device is a detection instrument for measuring the depth of the hardened layerthrough an ultrasonic backsc