The packaging steel strip roughing regulations was under pressure

Packaging steel strip roughing down procedures for roughing generally do not use more continuous rolling machine, its main task is sufficiently compressed, slab milk into the strip, so the quality is not high, but relative to the thickness of rolled piece and reduction mill bounce effect is small, so the pressure under the procedures of setting calculation and can use simpler methods. Down the content of the specifications, including feet the middle strip thickness and roughing of rolling out for various thickness for roughing mill frame number. Strip mills with roughing and finishing these two areas, the thickness distribution of the first task is to determine the thickness of roughing district export H. The determination of H is actually determine the load distribution between the roughing and finishing. 'button value is bigger, the roughing load loss, finishing load increase. Hours, on the other hand. In principle, as long as there is enough pure Zagreb unit, Hrc should take a few bigger. The strip thickness increased to reduce coarse milk time, shorten the roughing rolling time, improve the finishing temperature of Zagreb, but may increase load of finishing mill group ( Of finishing rolling time little influence on the strip thickness shall, first of all, to be decided according to the thickness, the general said for rolling thin finished product, with also thickness also pan corresponding thinning, but it's too thin strip rolling thin and there is no guarantee that the finished product for finishing rolling temperature, even to ensure the finishing rolling temperature, due to the low rolling temperature, finishing mill load will not reduce too much, may even increase. The strip thickness should be according to the actual arrangement and coarse finishing mill equipment capacity by optimizing design to determine. From reduce temperature drop to ensure finishing rolling temperature, also in order to reduce the melt temperature to save energy, modern mills developed the following technologies: ( 1) Adopt powerful roughing mill and finishing mill ( Especially the F0 - F3) 。 1700 mm strip, for example, allows the rolling force in the past 20 mn increased to 30 mn, rough mill main drive power increased from 5000 kw to 10000 kw, finishing main drive increased from 3500 kw to 8000 kw. So the quantity can be increased and increased for finishing the strip thickness. ( 2) Between before and after the roughing mill and finishing with insulation cover. ( 3) On yield is not very high constant speed after finishing mill group USES the roughing setting hot coiling box to reduce the temperature drop, especially make the strip temperature uniformity, reducing end temperature drop. ( 4) A long tunnel furnace increase in thin slab continuous casting and rolling rough finishing of the strip temperature.