Standards:
GBl8248 Chinese national standard
ASTMA519 Standard of American Society of Testing Materials

Application:
Used as seamless steel tubes of large calibers for manufacturing gas cylinders

Model No.of major steel tubes:
4130X

Diamensional tolerances:  
Types of steel tubes: Hot-rolled tubes 
Outer diameter:
 Tube sizes(mm) φ559
 Tolerances(mm) ±1.0%
Wall thickness:
 Tube sizes (mm) 17
 Tolerances(mm) -0%,+25
 
Mechanical properties: 
Standard codes: Q/321088HGB3
 Models of steel tubes 4130X
 Tensite strength(Mpa) 725~865
 Yield strength(Mpa) 485~735
 Yield ration ≤0.85
 Elongation(%) ≥20
 Absorbed-in-fracture energy(J) -40℃≥40
 Hardness 195~269HB

Chemical composition:  
Standard codes: Q/321088HGB3 
Models of steel tubes: 4130X 
Chemical compositions(%):  
 C 0.25~0.35
 Si 0.15~0.35
 Mn 0.40~0.90
 P ≤0.020
 S ≤0.010
 Cr 0.80~1.10
 Ni ≤0.25
 Cu ≤0.20
 Mo 0.15~0.25
 V ≤0.08