FUZZY-LOGIC MODELING AND CONTROL OF STEEL ROD QUENCHING AFTER HOT-ROLLING

Reinforced concrete rod produced by European Community countries must comply with standards that establish minimum strength and tensile prop erties along with other technological and geometrical characteristics; however, possible variability within the assigned limits is not speci fied, Consequently, a number of manufacturing methods are now used, wi th the result that over time the mechanical properties of these produc ts vary widely, Increased competition has led to the development of ne w procedures incorporating both process and quality control. One examp le is a process based on the heat treatment undergone by the metal bar s leaving the final stand of the rolling mill train, In this way, the mechanical and technological properties can be graduated, thereby enha ncing strength (particularly yield point) without altering the deforma bility of the material, This procedure does away with the need to alte r the chemical composition of the steel used to manufacture the rods, Process adjustment still relies on the experience of the production ma nager, however, This paper examines the possibility of applying fuzzy logic computer techniques to the heat treatment process in order to re nder it more rational and independent of operator unreliability.