In‐Line Heat Treatment and Hot Rolling

In‐line heat treatment of rolled materials is becoming increasingly used at hot rolling plants. The advantage of this method is the achievement of required material structure without the necessity of reheating.This paper describes a design procedure for cooling sections for the purpose of obtaining the required structure and mechanical properties. The procedure is typically used for the cooling of tubes, rails, long products and plates.Microstructure and nature of grains, grain size and composition determine the overall mechanical behaviour of steel. Heat treatment provides an efficient way to manipulate the properties of steel by controlling the cooling rate. The rate of cooling is defined by a heat transfer coefficient (HTC). Good controllability of HTC can be reached using either air‐water or water nozzles. Thus, an on‐line heat treatment with the assistance of spray nozzles enables a manufacturing process that can improve product performance by increasing steel strength, hardness and other desirable c...