BRICK FOR MOLTEN METAL FLOW RATE CONTROL DEVICE WHOSE SLIDING SURFACE ROUGHNESS IS ROUGH

摘要

PROBLEM TO BE SOLVED: To reduce the sliding resistance of a brick to be used in flow rate control of the molten metal. SOLUTION: In a molten metal flow rate control device of the slide valve type or rotary nozzle type which is provided on a molten metal container and controls the pouring amount, the surface roughness of at least one of sliding surfaces of bricks which slides on each other is in the range between 4.0 and 20.0μm in terms of the arithmetic mean roughness (Ra) specified in JIS.B0601 in order to determine the opening of a nozzle hole for adjusting the flow rate of the device.