High alloy pipe deformation strengthening is the use of steel reinforcement methods. Also known as hardening or strain hardening. The strength of the material at the macro (or the whole) the ability to resist deformation (or flow stress). Hardness is the ability of the material to resist localized plastic deformation (whether hardness, Vickers hardness, Rockwell hardness or Brinell). Both have similar corresponding relationship in many cases. Strength of the material, the greater the plastic deformation resistance, 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 materials in temperatures well below the recrystallization temperature of the alloy tube high-pressure steel pipe material, often use cold (cold deformation) means to make it through deformation strengthening to improve the strength. Thus, deformation strengthening essence recrystallization temperature of the material 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, the higher the flow stress. After deformation flow stress of steel tubes should not be equal before the flow stress deformation strengthening deformation plus incremental flow stress. Use of deformation strengthening to achieve high strength steel products, is a typical high-carbon steel cold-drawn steel wire and low-carbon low-alloy duplex steel cold-drawn steel wire.
With the degree of deformation increases, the strength of the material and hardness higher and higher, but its ductility and toughness are often getting lower and lower, more and more brittle, which need to take tough measures to improve the situation. Internal induced in the martensitic phase transformation during the cooling phase for hardening,its physical essence, it also belongs to deformation strengthening, but this time not from the external deformation, but from martensitic transformation process of crystal high-density bit itself shear generated by mistake.
Post time: Oct-15-2019