The heat treatments for cold drawn seamless steel pipes

Annealing. Refers to the heat treatment process in which metal materials are heated to an appropriate temperature, maintained for a certain period of time, and then slowly cooled. The main annealing processes include recrystallization annealing, stress relief annealing, spheroidizing annealing and complete annealing. The purpose of annealing is to reduce the hardness of cold drawn seamless steel pipe and improve the overall plasticity.

Normalizing fire. It refers to the heat treatment process of heating cold-drawn seamless steel pipe to Ac3 or 30~50℃ above Acm and waiting for a period of cooling in still air. It can improve the mechanical properties of seamless steel pipes, thereby improving the cutting processability, refining the grains, and eliminating structural defects.

Quenching. It refers to the heat treatment process in which seamless steel pipes are heated to a temperature above Ac3 or Ac1, and then cooled to an appropriate temperature to obtain a martensite structure. It can make the steel parts obtain the required martensitic structure, thereby greatly improving the hardness of the entire workpiece.

Tempering . It refers to the heat treatment process in which the steel pipe is heated to a temperature below Ac1 after being hardened, and then cooled to room temperature. Its main purpose is to eliminate the stress generated during quenching of steel parts, thereby achieving perfect hardness and wear resistance.

Editor: Lucas

Mail: lucas@yangtzesteel.com