Design Of Tianjin Iron And Steel Group CO.,LTD Rolling Mill Temperature Control

Since Tianjin Iron and Steel Group CO.,LTD Rolling mill has been launched in2006, on low temperature fine rolling (LTR) and quenching and tempering after rolling process (QTB) have already certainly succeed, and has accumulated a lot of experience. But now the LTR and QTB system manually adjust for water supply. In practical production, when using the QTB system to produce the different kinds of bars, operators need fumble and accumulate experience by them to satisfy performance of production. So Every time when replacing the varieties need longer adjust process, which will give the use of QTB LTR bring enormous difficulties and cannot guarantee stability of the product quality. In order to stabilize of the product quality and reduce quality of products for artificial factors, Tianjin Iron and Steel Group CO., LTD Rolling mill rolling mill has already upgraded and reconstructed LTR and QTB system for automatic control.Base on the principle of fine rolling and low-temperature LTR and QTB online heat treatment, and analyzes the reason which influences product performance by the low temperature rolling and quenching and tempering. LTR basic metallurgical principle is that below recrystallization temperature uses deformation make grain get refinement. QTB heat treatment is by changing the bar’s temperature track to improve bar mechanical properties. If the bar being through QTB and LTR system can greatly reduce the cost.Through dentally discussing the process of QTB and LTR. this paper analysis the composition of equipment and principle for the pressurization pumps, QTB and LTR. After that, this paper will by Siemens PLC achieve LTR and QTB process chain and human-computer interface and various operating for operators, also can improve various process chain and security. It achieves operators to LTR and QTB operation simplification, satisfy remote operation requirements. After operators can operate LTR and QTB system, this paper finish automatic control system for QTB and LTR. PID control is the most simple and effective control mode: particularly that parameter can be set by engineering. According to the principle of QTB and LTR, for the big lag we use feed-forward control, while for the flow rate and temperature we adopte cascade control, they can achieve desired objectives well. This paper use S7400series of Siemens PLC to achieve above functions. In The Siemens PLC. function blocks of PID named FB41can Sett various parameters simply, practical. The end of the paper we through the researching the function blocks realiza to set each parameter.