Medium and heavy plate is heated to the desired temperature for a certain period of time and then cooled with the selected cooling rate and cooling method to achieve the desired structure and properties. This process is called a heat treatment process. The heat treatment process consists of three stages of heating, holding and cooling. Different heating temperatures and cooling rates can be used depending on the purpose. Medium and heavy plate heat treatment commonly used three processes of normalizing, annealing and quenching and tempering. The purpose of heat treatment is to produce tempered plates with high tensile strength, high yield point, impact resistance, corrosion resistance, wear resistance and the like. Katalor can supply heavy plates cutting for shipbuilding steel.
Heat Treatment For Heavy Plates Cutting
Normalizing is to heat the steel plate to a temperature above the upper critical point A3 of about 30 to 50 ° C or higher, to austenitize the steel, and to homogenize the heat, and then cool it in a natural atmosphere to obtain a heat treatment process of the pearlite type structure. Normalizing can refine grains, uniform structure, improve impact energy and elongation, and eliminate internal stress in rolling.
Annealing is a heat treatment process in which the heavy plate is heated to a certain temperature above or below the critical point Ac1, kept for a certain period of time, and then slowly cooled to obtain a structure close to the equilibrium state. The essence is to heat and heat the steel plate to form a uniform austenite inside, and then cool with the furnace.
The quenching and tempering treatment is quenching and high temperature tempering, or medium temperature tempering, or normalizing combined heat treatment, the purpose of which is to achieve a higher comprehensive performance of the steel sheet. Quenching and tempering treatment is mostly used for medium carbon steel sheets and alloy structural steel sheets. For quenching and tempering treatment, some heavy steel plates with large stress after quenching should be tempered in time to avoid cracks. Quenching and tempering treatment should control the cooling rate of some steel plates during high temperature tempering to avoid temper brittleness.
