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Seamless steel tubes for normal structure

Seamless steel tubes for structural purposes, Seamless steel tubes for mechanical structures in GB/8162-2008 Standard. material include High-quality carbon steel and low alloy steel,such as 10,20,35,45 and Q345,Q460,Q490,42CrMo,35CrMo.
    Overview Application It Is Mainly Used To Make Carbon Structural Steel, Alloy Structural Steel and mechanical structures. Main Grade Grade Of Carbon Structural Steel: 10,20,35, 45,Q345,Q460,Q490,Q620,, Etc Grade Of Alloy Structural Steel: 42CrMo,35CrMo, Etc Chemical Component Steel Grade Quality level Chemical composition C Si Mn P S Nb V Ti Cr Ni Cu Nd Mo B Als" no greater than not less than  Q345 A 0.2 0.5 1.7 0.035 0.035       0.3 0.5 0.2 0.012 0.1 —— — B 0.035 0.035 C 0.03 0.03 0.07 0.15 0.2   0.015 D 0.18 0.03 0.025 E 0.025 0.02  Q390 A 0.2 0.5 1.7 0.035 0.035 0.07 0.2 0.2 0.3 0.5 0.2 0.015 0.1 — — B 0.035 0.035 C 0.03 0.03   0,015 D 0.03 0.025 E 0.025 0.02 Q42O A 0.2 0.5 1.7 0.035 0.035 0.07 0.2 0.2 0.3 0.8 0.2 0.015 0.2 —— —— B 0.035 0.035 C 0.03 0.03 0.015 D 0.03 0.025 E 0.025 0.02 Q46O C 0.2 0.6 1.8 0.03 0.03 0.11 0.2 0.2 0.3 0.8 0.2 0.015 0.2 0.005 0.015 D 0.03 0.025 E 0.025 0.02 Q500 C 0J8 0.6 1.8 0.025 0.02 0.11 0.2 0.2 0.6 0.8 0.2 0.015 0.2 0.005 0.015 D 0.025 0.015 E 0.02 0.01 Q550 C 0.18 0.6 2 0.025 0,020 0.11 0.2 0.2 0.8 0.8 0.2 0.015 0.3 0.005 0.015 D 0.025 0,015 E 0.02 0.01 Q62O C 0.18 0.6 2 0.025 0.02 0.11 0.2 0.2 1 0.8 0.2 0.015 0.3 0.005 0.015 D 0.025 0.015 E 0.02 0.01 A. In addition to Q345A and Q345B grades, the steel should contain at least one of the refined grain elements Al, Nb, V, and Ti. According to the needs, the supplier can add one or more refined grain elements. The maximum value shall be as specified in the table. When combined, Nb + V + Ti is not more than 0.22%b. For Q345, Q390, Q420 and Q46O grades, Mo + Cr is not greater than 0.30%c. When Cr and Ni of each grade are used as residual elements, the content of Cr and Ni should not be greater than 0.30%; when it is necessary to add, the content should meet the requirements in the table or be determined by the supplier and the buyer through consultation.d. If the supplier can ensure that the nitrogen content meets the requirements in the table, the nitrogen content analysis may not be performed. If Al, Nb, V, Ti and other alloy elements with nitrogen fixation are added to the steel, the nitrogen content is not limited. The nitrogen fixation content should be specified in the quality certificate. E. When using full aluminum, the total aluminum content Alt ≥ 0020%. Grade Carbon equivalent CEV (mass fraction) /% Nominal wall thickness s≤ 16mm Nominal wall thickness S2>16 mm〜30 mm Nominal wall thickness S>30mm Hot rolled or normalized normalized Quenching +tempering Hot rolled or normalized Quenching +tempering Hot rolled or normalized Quenching +tempering Q345 <0.45 — <0.47 — <0.48 一 Q390 <0.46 一 W0.48 — <0.49 — Q420 <0.48 一 <0.50 <0.48 <0.52 <0,48 Q460 <0.53 <0.48 W0.55 <0.50 <0.55 W0.50 Q500 一 <0.48 一 <0.50 一 W0.50 Q550 — <0.48 .一 <0.50 一 <0.50 Q62O — <0.50 — <0.52 — W0.52 Q690 — <0.50 — <0.52 — W0.52 Mechanical Property Mechanical properties of high-quality carbon steel structural steel and low-alloy high-strength structural steel pipes Grade Quality level Yield Strength Lower yield strength Elongation after breaking Impact test   Nominal wall thickness temperature Absorb energy <16 mm >16 mm〜 〉30 mm   30 mm not less than not less than 10 — >335 205 195 185 24 — — 15 — >375 225 215 205 22 — 一 20 —— >410 245 235 225 20 — — 25 — >450 275 265 255 18 — — 35 — >510 305 295 285 17 一 — 45 — 2590 335 325 315 14 — — 20Mn —• >450 275 265 255 20 — 一 25Mn — >490 295 285 275 18 — — Q345 A 470—630 345 325 295 20 — 一 B 4~20 34 C 21 0 D -20 E -40 27 Q39O A 490—650 390 370 350 18     B 20 34 C 19 0 D -20 E -40 27 Q42O A 520〜680 420 400 380 18     B 20 34 C 19 0 D -20 E -40 27 Q46O C 550〜720 460 440 420 17 0 34 D -20 E -40 27 Q500 C 610〜770 500 480 440 17 0 55 D -20 47 E -40 31 Q550 C 670〜830 550 530 490 16 0 55 D -20 47 E -40 31 Q62O C 710〜880 620 590 550 15 0 55 D -20 47 E -40 31 Q690 C 770〜94。 690 660 620 14 0 55 D -20 47 E -40 31 Mechanical properties of alloy steel pipes NO Grade Recommended heat treatment regime Tensile properties Annealed or high temperature tempered steel pipe Delivery condition Brinell hardness HBW Quenching (normalizing) Tempering Yield StrengthMPa Tensile Strength MPa Elongation after breaking A% temperature Coolant Temperature Coolant Frirst Second not less than no greater than 1 40Mn2 840   Water, oil 540 Water, oil 885 735 12 217 2 45Mn2 840   Water,oil 550 Water, oil 885 735 10 217 3 27SiMn 920   Water 450 Water, oil 980 835 12 217 4 40MnBc 850   oil 500 Water, oil 980 785 10 207 5 45MnBc 840   oil 500 Water, oil 1 030 835 9 217 6 20Mn2Bc'f 880   oil 200 Water, air 980 785 10 187 7 20CrdJ 880 800 Water,oil 200 Water, air 835 540 10 179 785 490 10 179 8 30Cr 860   oil 500 Water, oil 885 685 11 187 9 35Cr 860   oil 500 Water, oil 930 735 11 207 10 40Cr 850   oil 520 Water, oil 980 785 9 207 11 45Cr 840   oil 520 Water, oil 1 030 835 9 217 12 50Cr 830   oil 520 Water, oil 1 080 930 9 229 13 38CrSi 900   oil 600 Water, oil 980 835 12 255 14 20CrModJ 880   Water,oil 500 Water, oil 885 685 11 197 845 635 12 197 15 35CrMo 850   oil 550 Water, oil 980 835 12 229 16 42CrMo 850   oil 560 Water, oil 1 080 930 12 217 17 38CrMoAld 940   Water, oil 640 Water, oil 980 835 12 229 930 785 14 229 18 50CrVA 860   oil 500 Water, oil 1 275 1 130 10 255 19 2OCrMn 850   oil 200 Water、air 930 735 10 187 20 20CrMnSif 880   oil 480 Water, oil 785 635 12 207 21 3OCrMnSif 880   oil 520 Water, oil 1 080 885 8 229 980 835 10 229 22 35CrMnSiA£ 880   oil 230 Water、air 1 620   9 229 23 20CrMnTie-f 880 870 oil 200 Water、air 1 080 835 10 217 24 30CrMnTie*f 880 850 oil 200 Water、air 1 470   9 229 25 12CrNi2 860 780 Water,oil 200 Water、air 785 590 12 207 26 12CrNi3 860 780 oil 200 Water、air 930 685 11 217 27 12Cr2Ni4 860 780 oil 200 Water、air 1 080 835 10 269 28 40CrNiMoA 850 —— oil 600 Water、air 980 835 12 269 29 45CrNiMoVA 860 — oil 460 oil 1 470 1 325 7 269 a. Allowable adjustment range of heat treatment temperature listed in the table: quenching ± 15 ℃, low temperature tempering ± 20 ℃, high temperature tempering soil 50 ℃.b. In the tensile test, transverse or longitudinal samples can be taken. In case of disagreement, the longitudinal sample is used as the basis for arbitration.c. Boron-containing steel can be normalized before quenching, and the normalizing temperature should not be higher than its quenching temperature.d. Delivery according to a set of data specified by the demander. When the demander has not specified, delivery can be made according to any of the data.e. The first quenching of titanium steel with Ming Meng can be replaced by normalizing.f. Isothermal quenching at 280 C ~320 C. g. In the tensile test, if Rel cannot be measured, Rp0.2 can be measured instead of Rel.   Tolerance Allowable deviation of outer diameter of steel pipe Type of steel pipe Allowable Tolerance Hot rolled steel pipe ± 1% D or ± 0.5, whichever is greater Cold drawn steel pipe Soil 0,75% D or soil 0.3, whichever is greater   Allowable deviation of wall thickness of hot rolled (extended) steel pipe Type of steel pipe D S/D Allowable Tolerance Hot rolled steel pipe <102 — ± 12.5% S or ± 0.4, whichever is greater >102 <0.05 ± 15% S or ± 0,4, whichever is greater >0.05 〜0.10 ± 12.5% S or ± 0.4, whichever is greater >0.10 + 12.5%S -10%S Heat expanded steel pipe 一 土 15%S Allowable deviation of wall thickness of cold drawn (rolled) steel pipe Type of steel pipe S Allowable Tolerance Cold drawing (rolling) V + 15% S Or 0.15, whichever is greater —10% S >3 — 10 + 12.5%S —10%S >10 土 10%S Test Requirement Chemical composition,Stretch,Hardness,Shock,Squash,Bending,Ultrasonic testing,Eddy current,detection,Leak detection,Galvanized Product Detail Mechanical/Chemical&Fertilizer Pipes GB/T 8162-2008 ASTM A519-2006 BS EN 10210-1-2006 ASTM A53/A53M-2012 GB 9948-2006 GB 6479-2013 GB/T 17396-2009