Non-standard steel pipe performance index
Analysis of Performance Indices of Special-Shaped Steel Pipes - Plasticity
Plasticity refers to the ability of metallic materials to undergo plastic deformation (deformation) under load without breaking.

2. Analysis of Non-standard Steel Pipe Performance Index - Hardness
Hardness is a measure of the degree of softness or hardness of a metal material. The commonly used method for measuring hardness in current production is the indentation hardness test, which involves pressing a stylus of a certain geometric shape into the surface of the metal material being tested under a specific load. The hardness value is determined based on the degree of indentation.
Common methods include Brinell hardness (HB), Rockwell hardness (HRA, HRB, HRC), and Vickers hardness (HV).

3. Analysis of Non-standard Steel Pipe Performance - Fatigue
The discussed strength, plasticity, and hardness are all mechanical property indicators of metals under static load conditions. In reality, many machine parts operate under cyclic loads, where fatigue in the parts occurs under such conditions.