Cylinder Tube Production Process

 Cylinder Tube Production ProcessMechanical Property  Supply condition Steel grade  Cold finished Hard)( BK)  Cold drawn (BK+S) and stress-relieved   Hardness HB  Tensile strength MPa Elongation ( %) Tensile strength MPa Yield strength MPa Elongation ( %) 20# >550>8 >520>375 >12 175 45# >650>5>600>520>12 207 ST52 >640>5>600>520>15 190 25Mn >640>5 >600>510>15 195 27SiMn >840>5 >800>720>10 230Chemical Composition  Steel GradeCSi MnPSCuNiCr V Nb Ti Al 20# 0.17~0.23 0.17~0.370.35~0.65  0.035 0.0350.25 0.25 0.25 / / //  45# 0.42~0.50 0.17~0.370.50~0.80 0.025 0.025 0.20 0.20 0.25 / / / / 25Mn 0.22~0.29 0.17~0.37 0.70~1.00 0.03 0.03 0.20 0.20 0.25 / / / / 27SiMn 0.24~0.32 1.10~1.401.10~1.40 0.035 0.035 0.30 0.30 0.30 / / / / Q345B(St52) 0.20  0.551.00~1.60 0.04 0.04 / / / 0.02~0.15 0.015~0.060.02~0.20  / Q345D(St52).18  0.551.00~1.60 0.03 0.03 / / /0.02~0.15  0.15~0.06 0.02~0.200.15