What is the annealing heat treatment of cold rolled sheet?

Cold rolled sheet refers to steel whose width is greater than the height of steel, and is mainly used for industrial materials such as steel structure manufacturing, machinery manufacturing, automobile industry, mining machinery, and hoisting machinery. Therefore, the requirements for cold-rolled steel sheets are more stringent, and the requirements for different cold-rolled steel sheet production processes are also very strict. Among them, the annealing treatment of cold-rolled steel sheets is a very strict process.

Cold rolled sheet annealing is a metal heat treatment method that heats steel to a phase transition or partial phase transition temperature. After keeping it warm for a period of time, it is cooled at an appropriate speed in the furnace or in a medium with poor thermal conductivity. Annealing of cold-rolled steel sheets not only eliminates and improves the structural defects and residual stress left over from the previous process, prevents deformation and cracking of the workpiece, but also softens the steel used for cutting, refines the grains, and improves the microstructure. The mechanical properties of the workpiece were tested and prepared for the follow-up process. So annealing is semi-finished product heat treatment, also known as pre-heat treatment. Normalizing is a heat treatment in which steel is heated above the critical temperature to transform the steel into average austenite, and then it is naturally cooled in air. If the cold-rolled sheet is not properly annealed, it will affect the quality and performance of the cold-rolled steel sheet.