High-pressure alloy pipe deformation strengthening is using the method of deformation of steel reinforcement. Also known as the strain hardening or work hardening. The strength of the material at the macro (or a whole) the ability to resist deformation (or flow stress). Hardness is the ability of the material to resist plastic deformation localized (whether micro-hardness, Vickers hardness, Rockwell hardness or Brinell hardness). Both have similar corresponding relationship in many cases. Strength of the material, the greater the resistance to plastic deformation, the higher the hardness value. Conversely, the higher the hardness of the material, the material may be due to increased brittleness, its strength is not fully reflected in such strength index value is not high.


For longer subjected to heat treatment, and the use of the material in temperatures well below the recrystallization temperature of the high-pressure alloy pipe steel pipe material (such as low-carbon low-alloy steel), often use cold (cold deformation) so that by means of deformation strengthening to improve strength. Thus, deformation strengthening essence is in the recrystallization temperature of the material in the following cold deformation, with the degree of deformation (strain) is increased, resulting in a high density of dislocations (crystal defects), the higher the dislocation density in the crystal, The greater the degree of enhancement, namely the higher flow stress. After deformation flow stress of steel should not be equal before deformation flow stress plus incremental deformation strengthening flow stress. Use of deformation strengthening to achieve high strength steel products, typical is the high-carbon steel cold-drawn steel wire and low carbon low-alloy duplex steel cold-drawn steel wire.


With the increase of the degree of deformation, material strength and hardness higher and higher, but its ductility and toughness are often getting lower and lower, more and more brittle, which requires tough to take appropriate measures to improve the situation. Internal induced in the martensitic phase transformation phase cooling for hardening, its physical essence, it also belongs to deformation strengthening, but this time not from the external deformation, but the process of martensitic transformation from crystal High-density place itself shear generated by mistake.