Solutions for the Global Metals Industry

Coiling Temperature ControlSteel customers today demand that mills produce specific mechanical properties for their products, such as yield strength,tensile strength, and elongation. The coiling temperature control maintains the rate of cooling and the final temperature(the temperature-time profile) of the strip to obtain the desired metal properties as it enters the coilers.TMEIC’s Coiling TemperatureControl (CTC) features:Physics-based ModelsThe model of the coolingprocess generates coolingwater flow setpoints,which are sent to the level1 control to produce thedesired temperature-timeprofile as the strip movestoward the coilers. A processmodel encompasses variouscoiling temperature controlstrategies.Metallurgical-based ModelsThe CTC model includesthe effects of the steelphase transformation foraccurate prediction of thetemperature-time profilerequired for the optimummechanical properties.MODELSSTRIP SPEEDPROFILEMILL EXITSENSORSTRACKINGPIECE SAMPLEFEEDBACKIN-COILFEEDFORWARDFINISHINGSPEEDSENSORSFM EXITTEMP.EARLY COOLINGZONEMODELSCOILINGTEMPERATUREFEEDBACKIN-COILFEEDBACKINTERMEDIATECOOLING ZONEFEEDBACKFEEDBACKSYSTEMPARAMETERSIN-COILFEEDFORWARDS ENSORSBOTTOMPYROTRACKINGPIECE SAMPLEMODELSCOILINGTEMPERATUREFEEDBACKIN-COILVERNIERSENSORSBOTTOMPYROSENSORSCOILINGTEMP.LATE COOLINGZONE - VERNIERCoiler Temperature Control SystemEarlyCoolingDUAL PHASE COOLINGRadiationLateCoolingDetails of the Coiling Temperature Control ModelThe rate of cooling, the intermediate, and final temperature, are tied tothe desired mechanical properties, thus precise cooling control is critical.TMEIC’s Dual Phase Cooling model illustrated above is described here.Early Coiling Temperature Cooling ModelThe CTC model takes finishing mill exit speed and temperature plus feedback from the intermediate zone and calculatesthe level 1 cooling water flow setpoints for the early cooling zone to achieve the desired quench rate and intermediatetemperature.Dual Phase/Interrupted CoolingThe combination of interrupted cooling and modeling of low target temperatures achieves specific steel structures such asthe bainitic and martensitic.Late Coiling Temperature Cooling ModelThis model takes the final and intermediate temperatures and calculates the late (vernier) cooling flow setpoints. Thecoiling temperature control model utilizes several techniques including feedback, feedforward, and vernier temperaturecontrol to meet the process objectives.© 2011 TMEIC Corporation. All Rights Reserved.Page 11 of 40