Cold drawing seamless pipe for precision mechanical structure, hydraulic equipment and good surface finish cold drawn or cold-rolled precision seamless steel tubes. High-precision drawing that diameter size accuracy (tolerance) strict, the outer surface finish, roundness, straightness, thickness uniformity is good.
Cold drawn seamless steel pipe heat treatment:
(1) cold drawn steel annealing: Refers to the metal material heated to the right temperature, to maintain a certain period of time, and then slowly cooling the heat treatment process. Common annealing process are: recrystallization annealing, stress relief, ball annealing, complete annealing and so on. The purpose of annealing: Mainly to reduce the hardness of the metal material to improve the plasticity, cutting processing Harix pressure processing, reduce residual stress and improve the uniformity of the organization and composition, heat treatment may be or tissue preparation.
(2) Normal cold drawn steel: refers to the steel or steel AC3 or ACM heating (the critical temperature of the steel) over 30 ~ 50 ℃, to keep the air-cooled heat treatment process for the appropriate time. The purpose of normalizing: Mainly to improve the mechanical properties of low-carbon steel to improve machining performance, grain refinement, the elimination of tissue defects, prepared for the heat treatment, after the preparation of the organization.
(3) Cold-drawn steel quenching: refers to heating above the temperature of Ac3 or Ac1 (the lower critical temperature of steel), and then cooling to obtain martensite (or shell heat-treated tissue) at an appropriate speed. Common salt bath quenching process quenching, martensitic quenching, surface hardening and partial quenching Austempering. The purpose of quenching: the need to obtain martensite steel to improve the hardness, strength and wear resistance of the workpiece, heat treatment after the preparation and preparation of the organization.
(4) cold drawn steel tempering: hardened steel, and then heated to below Ac1 temperature, heat a certain time, and then cooled to room temperature, heat treatment process. Tempering of a common tempering, tempering, tempering and repeated tempering. The purpose of tempering: Mainly quenched steel produced stress relief, the steel has a high hardness and wear resistance, and has the required plasticity and toughness.
(5) cold drawn steel quenching: refers to the heat treatment of steel or composite steel quenching and tempering. For quenched and tempered steel. Generally refers to carbon steel and alloy steel carbon structure.
(6) Cold-drawn steel chemical treatment: refers to the heat treatment of metal or alloy workpiece placed in a constant temperature medium, one or several elements into its surface, changing its chemical composition, microstructure and properties of the heat treatment process. Common chemical heat treatment process are: carburizing, nitriding, carbonitriding, aluminizing boron penetration. The purpose of chemical treatment: mainly to improve the surface hardness of steel, wear resistance, corrosion resistance, fatigue resistance and oxidation resistance.
(7) cold drawn molten steel processing: the alloy is heated to a high temperature single-phase area to maintain a constant temperature, the phase completely dissolved quickly dissolved into the solid solution to obtain supersaturated solid solution heat treatment process. The purpose of solution treatment: The main is to improve the toughness and toughness of steel and alloy preparation for precipitation hardening.