20# seamless steel pipe is a low carbon steel pipe. Carbon steel is generally divided into three types: low carbon steel, medium carbon steel and high carbon steel. Among them, 45# steel is medium carbon steel, and steel below 45# is low carbon steel. Steel above 45# is low carbon steel. 45# is high carbon steel. If there are no special requirements for seamless steel pipes, 20# seamless steel pipes are generally used.
20# seamless steel pipe is made of 20# steel, with slightly higher strength than 15#, little quenching, and no temper brittleness. It has high cold deformation plasticity and is generally used for bending, rolling, flanging and hammer arching. It has good welding performance in arc welding and contact welding. The thickness is small during gas welding and cracks are prone to occur on parts with strict appearance requirements or complex shapes. The cold drawn or normalized state has better machinability than the annealed state, and is generally used to manufacture workpieces with low stress and high toughness requirements.
chemical composition:
Carbon C: 0.17%～0.20%
Silicon Si: 0.17%～0.37%
Manganese Mn: 0.35%～0.65%
Sulfur S: ≤0.035%
Phosphorus P: ≤0.035%
Chromium Cr: ≤0.25%
Nickel Ni: ≤0.25%
Copper Cu: ≤0.25%
Mechanical properties:
Tensile strength σb (MPa): ≥410(42)
Yield strength σs (MPa): ≥245(25)
Elongation δ (%): ≥25
Reduction of area ψ (%): ≥5,
Hardness: not heat treated, ≤156HB,
Sample size: Sample size 25mm
Heat treatment specifications and metallographic structure:
Heat treatment specifications: normalizing, 910℃, air cooling.
Metallographic structure: ferrite + pearlite.
Delivery status: Delivery without heat treatment or heat treatment (annealing, normalizing or high temperature tempering).
If the product is required to be delivered in a heat-treated state, it should be stated in the contract. If it is not stated, it will be delivered without heat treatment.
