Quenching and tempering is a heat-treatment method for high-quality heavy plates. Quenching and tempering consists of a two-stage heat-treatment process. Stage 1 includes hardening, in which the plate is austenitized to approximately 900°C and then quickly cooled. The material is water-quenched in a quench unit, in which the plate is clamped to avoid warpage. Stage 2 consists of tempering the material to obtain the desired material properties. Quenching and tempering achieves an extremely fine-grained and homogeneous microstructure. Quenched and tempered steel is characterized by high strength and good ductility.