When high-precision steel pipe undergoes plastic deformation, the strength and hardness of the metal increase, while the decrease in plasticity and toughness is called cold deformation strengthening (also known as work hardening). The reason for cold deformation strengthening is generally considered that during the plastic deformation process, as the amount of deformation increases, the dislocation density increases, and a series of interactions occur, which hinder the movement of the dislocations; at the same time, the crystal grains will also be broken and become Thin strips, the grain boundaries become blurred, forming the so-called "fibrous structure". The greater the degree of deformation of Wuxi precision steel pipes, the higher the dislocation density, the greater the resistance to dislocation movement and the greater the resistance to plastic deformation, the higher its strength and hardness, but the lower its plastic toughness.