PURPOSE:To reduce the rolling reduction ratio in the manufacture of an extremely thick-wall steel plate by a hot rolling while superposing a continuously cast slab or a thick wall steel plate manufactured from the continuously cast slab. CONSTITUTION:At the time of making a composite slab by superposing a continuously cast slab 1 or a thick wall steel plate 2, an amorphous metal is inserted between superposed surfaces and a central part in the thickness direction of the continuously cast slab 1 is made not to coincide with a central part in the thickness direction of a product. Then the hot rolling is executed by heating the composite slab over the melting temperature of the amorphous metal. The fault in interior quality is excluded even under a condition that the rolling reduction ratio in the hot rolling is low such as >=1.6, and the extremely thick wall steel plate of the thickness >=100mm having excellent quality can be manufactured.

Manufacture of extremely thick wall steel plate

PURPOSE:To surely prevent rear-end collision when the car behind detected with a backward radar is brought off from a beam area at approaching this vehicle by synthetically judging a danger of rear-end collision based on data at existing in the beam area. CONSTITUTION:A control circuit 16 controls to drive a backward sensor 20 through a driving circuit 22, and judges existence of the car behind in a prescribed distance based on the detected signal from the backward sensor 20. When the car behind exists, relative distance and speed between this vehicle and the car behind are computed based on the detected signal from a vehicle speed detecting circuit 10 for detecting the running speed of this vehicle. When a danger of rear-end collision exists at present by changing the advancing direction of this vehicle, a waning device 26 is actuated through a driving circuit 24, based on the detected signal from a steering angle detecting circuit 12 and the like. Further, when a danger of rear-end collision exists at changing the advancing direction after a prescribed time, a warning is given on confirming this.

Akutsu Eisaku

Papers

Rear-end collision preventing device with rear direction radar