Introduction of 20# seamless pipe

20# seamless pipe is one of our main production in our company , we have 200 tons cargo in stock at present ,Here is the detail introduction of 20# seamless pipe  :
20 # seamless steel pipe is a kind low carbon material steel pipe, carbon steel is generally divided into low carbon steel, medium carbon steel and high carbon steel, which is suitable for medium carbon steel 45 # steel, lower than 45# called low carbon steel, higher than 45 # called high carbon steel, if there is no special requirements about seamless pipe , generally adopt # 20 seamless steel pipe this material.
The strength of 20# is slightly higher than 15 #, rarely quenching, no temper brittleness.High cold deformation plasticity , the general for bending, rolling, flanging and hammer processing . With good performance at Arc welding and resistance welding. when thickness is small during welding, strict shape or complex shape parts prone to crack. cold drawn of Cutting machining at normalizing condition is better than  annealing condition , commonly used in the manufacture high stress but not big and tough requirements artifacts.
Type : High quality carbon structural steel
Grade: 20#
Standard :GB8162-2008
Chemical composition :
C ：0.17%～0.2%  Si：0.17%～0.37%  Mn：0.35%～0.65%  S ：≤0.035%
P ：≤0.035%  Cr：≤0.25%  Ni：≤0.25%  Cu：≤0.25%
Mechanical properties：
Tensile strength σb (MPa)：≥410(42)
The yield strengthσs (MPa)：≥245(25)
Elongationδ5 (%)：≥25
Reduction of area ψ (%)：≥5
Hardness ：Without heat treatment ,≤156HB
Sample Size :25mm
Heat treatment specification and metallographic organization:
Heat treatment specification: fire, 910 ℃, air cooling.Metallographic organization: ferrite + pearlite.
Delivery status: with no heat treatment or heat treatment (annealing, normalizing or high temperature tempering) status of delivery.For heat treatment state delivery should be indicated in the contract, not specified by the heat treatment delivery.
1.1 steel pipe nominal diameter of 88.9 mm, nominal wall thickness of 6.45 mm.
1.2 steel pipe diameter and wall thickness deviation should be allowed to meet the provisions of the table 1.Table to allow outside diameter deviation + 0.50 mm to 0.20 mm thickness allowable deviation + 0.97 mm to 0.77 mm.
2. The usual length of steel tube is 9400 mm to 9750 mm.
Shape bending steel pipe shall not be greater than 1.0 3.1 3.1 mm/m.
3.2 steel tube on both ends of the end face should be perpendicular to the pipe axis, incision burrs should be removed.
4. Weight steel pipe according to the actual weight delivery, can also according to the theory of weight.Steel pipe weight is 13.115 kg/m
Finished product chemical composition of the steel pipe deviation should be allowed to meet the relevant provisions of GB/T 222.
6. Delivery status Steel pipe in hot rolled state delivery.
Mechanical properties of the 7. By proper heat treatment, the mechanical properties of the steel pipe should be reached in API SPEC 5 ct grade N80 steel requirements.
8. The compactness steel pipe shall be carried out by the root density of eddy current flaw detection in test tube, eddy current flaw detection contrast sample artificial defects phi is 2.2 mm + / - 0.01 mm hole diameter.