Design Of Temperature Detection System For Yongin Specialty Steels

Continuous billet rolling is a kind of technology to put liquid steel into the continuous casting machine to rolling billet, and billet does not require cooling who directly into the hot strip mill rolling molding steel after a holding time. The temperature is very important for the steel’s hardness, strength, toughness and plasticity in the process of rolling. So, research on temperature detection system is important for steel rolling production, it can improve the quality of the products.The main work and achievements:1. Completed the hardware design and the main componet selection of the temperature detection system. The temperature sensors in this paper need to1600℃, and have good linearity, suitable for long distance transmission, so chooseed the thermocouple temperature transmitter for standard output4-20mA. The A/D converter used the LM331voltage to frequency converter and it’s interference immunity is better than AD0809. The slave MCU used the STC12series MCU, and the host MCU used the ATmegal6MCU who had larger capacity memorizer and abundant hardware interface electric circuit, it needed to deal with the signal from STC. The data transmission between the detection points choosed the RS-485.2. Researched the influence by the capacitance CL to the change-over electric circuit’linearity in the voltage/frequency conversion circuit by LM331. Through the experiment, got the0.9%linearity by adjusted the size of CL.3. The electronic display screens used the8inch LED which has high brightness, low cost and easy to control. Designed the drive circuit of the digital tube.4. Completed the software design of the slave MCU and the host MCU of the temperature detection system.5. Low temperature linearity after the system run. It can greatly improve the linearity by to improve the input impedance.