Coiling Temperature Control of Strip Tail for Minimizing the Deviation of Mechanical Properties in Mini-Mill Process

Strip Tail부 재질 편차 감소를 위한 권취 온도 미단 제어 정도 향상

This document illustrates the way to control of coiling temperature(CTC) of stip tail part in minimill process. The coiling temperature (CT) is very important fact in hot rolling process because the mechnical properties of strip depend on it. In mini-mill pocess, the speed pattern of rolling is different from that of conventional hot rolling. We have a lot of difficulties in controlling the coiling temperature at strip tail part, because after the strip tail is passed out the final stand, it's impossible to control the coiling temperature by using coiling speed. So we have CT deveiation in this gauge, about 160$^{\circ}C$ below in comparison with target CT. It's clear that deviation of mechanical properties(tensile strength, vield ratio etc) of strip to direction of length is so large, so we could not produce middle carbon steel, like this temperature condition. New coiling temperature control of strip especially in strip tail was developed. An innovative method for calculate the deceleration speed of strip tail has been implemented in CTC program, so called