The general heat treatment processes for cold-drawn steel pipes are as follows:

1. Quenching and Tempering: This refers to a combined heat treatment process involving quenching and tempering of steel or steel components. Steel used for quenching and tempering is called quenched and tempered steel. It generally refers to medium-carbon structural steel and medium-carbon alloy structural steel.

   
   

   

2. Annealing: Common annealing processes include recrystallization annealing, stress-relief annealing, spheroidizing annealing, and full annealing. The purpose of annealing is primarily to reduce the hardness of the metal material, improve its plasticity to facilitate machining or pressure processing, reduce residual stress, improve the homogenization of the microstructure and composition, or prepare the microstructure for subsequent heat treatment.

3. Quenching: Common quenching processes include salt bath quenching, martensitic graded quenching, bainitic isothermal quenching, surface quenching, and local quenching. The purpose of quenching is to obtain the desired martensitic structure in the steel component, improve the workpiece's hardness, strength, and wear resistance, and prepare the microstructure for subsequent heat treatment. 4. Normalizing of Cold-Drawn Steel Pipes: The purpose of normalizing is primarily to improve the mechanical properties of low-carbon steel, enhance machinability, refine grains, eliminate structural defects, and prepare the microstructure for subsequent heat treatment.

5. Tempering of Cold-Drawn Steel Pipes: Common tempering processes include low-temperature tempering, medium-temperature tempering, high-temperature tempering, and multiple tempering. The purpose of tempering is mainly to eliminate the stress generated during quenching, giving the steel high hardness and wear resistance, as well as the required plasticity and toughness.