When the precision seamless steel pipe is quenched and quenched, the entire section of the workpiece is required to be hardened, so that the workpiece is obtained by fine-stacked quenched martensite. By tempering at a high temperature, a microstructure mainly composed of a uniform tempering body is obtained.
Normalizing: Normalizing is a heat treatment method in which the steel is heated above the critical temperature to completely transform the steel into uniform austenite and then naturally cool in the air. It can eliminate the network cementite of hypereutectoid steel. It can be used to refine the crystal lattice of hypoeutectoid steel and improve the comprehensive mechanical properties. It is economical to replace the tempering process with the normalized fire for the less demanding parts.
Quenching: quenching is to heat the steel above the critical temperature, keep it for a period of time, and then quickly put it into the quenching agent, so that its temperature suddenly drops, and it is rapidly cooled at a speed greater than the critical cooling rate, and martensite is obtained. Heat treatment method for unbalanced tissue. Quenching increases the strength and hardness of steel, but reduces its ductility. Quenching agents commonly used in quenching are: water, oil, alkaline water and salt solutions. The high-speed steel quenching agent can be "wind", so high-speed steel is also called "wind steel."
Tempering: Reheat the quenched steel to a certain temperature and then cool it to a certain degree by tempering. Its purpose is to eliminate the internal stress generated by quenching and reduce the hardness and brittleness to achieve the desired mechanical properties. The tempering is divided into three categories: high temperature tempering, medium temperature tempering and low temperature tempering. The tempering is mostly used in combination with quenching and normalizing.
Quenching and tempering treatment: The heat treatment method of high temperature tempering after quenching becomes quenching and tempering treatment. High temperature tempering refers to tempering between 500-650 °C. Quenching and tempering can make the properties and materials of steel get a large degree of quenching and tempering, and its strength, plasticity and toughness are good, and it has good comprehensive mechanical properties.
www.skivingtubelw.com
