Hot-rolled coils for the manufacture of large-diameter pipes

Usage

Salzgitter Flachstahl supplies hot-rolled wide coil for the manufacture of large-diameter pipes. Large-diameter pipes are predominantly used for carrying gas and liquids under high pressure and as piling pipes. There are different manufacturing processes.

The technological values of the finished pipe are laid down in the standards API 5L and EN 10208-2. Salzgitter Flachstahl warrants the hot-rolled wide coil standards. When ordering hot-rolled wide coil for pipe manufacturing, the necessary technical key data have to be coordinated. Information about pipe diameter and welding process allow an estimation of the pipe data.

Standards1)

International Material No. Europe DE US FK2)
ISO 3183 EN 10208-2 3) DIN 17172 3) API 5L
L210 1.8713 - StE 210.7 Grade A A
L245 1.8723 - - Grade B A
L290 1.8728 - - X42 B
L320 1.8729 - StE 320.7 X46 C
L360 1.8730 - - X52 C
L390 1.8724 - - X56 C
L415 1.8725 - - X60 D
L450 1.8726 - - X65 D
L485 1.8727 - - X70 D
L245N/NE 1.8790/1.0457 L245NB StE 240.7 Grade BN A
L290N/NE 1.8791/1.0484 L290NB StE 290.7 X42N B
L320N 1.8792 - - X46N C
L360N/NE 1.8793/1.0582 L360NB StE 360.7 X52N C
L390N 1.8970 - - X56N D
L415N/NE 1.8736/1.8972 L415NB - X60N D
L245M/ME 1.8746/1.0418 L245MB StE 240.7 Grade BM A
L290M/ME 1.8747/1.0429 L290MB StE 290.7 X42M B
L320M 1.8748 - - X46M C
L360M/ME 1.8749/1.0578 L360MB StE 360.7 X52M C
L390M 1.8971 - StE 385.7 X56M C
L415M/ME/MS 1.8752/1.8973/1.8766 L415MB StE 415.7 X60M D
L450M/ME/MS 1.8754/1.8975/1.8767 L450MB StE 445.7 X65M D
L485M/ME 1.8756/1.8977 L485MB StE 480.7 X70M D
  1. Other standards or specifications by agreement
  2. FK = Tensile strength class, Dimensions
  3. invalid standard

Chemical composition in percent by weight [%] (Heat analysis)

Grade C2) Si Mn2) P S V Nb Ti Other CEIIW CEPcm
max. max. max. max. max. max. max. max. max. max.
L210 / A 0.22 - 0.90 0.030 0.030 - - - 1,7) - -
L245 / B 0.26 - 1.20 0.030 0.030 3,4) 3,4) 4) 1,7) - -
L290 / X42 0.26 - 1.30 0.030 0.030 4) 4) 4) 1,7) - -
L320 / X46 0.26 - 1.40 0.030 0.030 4) 4) 4) 1,7) - -
L360 / X52 0.26 - 1.40 0.030 0.030 4) 4) 4) 1,7) - -
L390 / X56 0.26 - 1.40 0.030 0.030 4) 4) 4) 1,7) - -
L415 / X60 0,265) - 1,405) 0.030 0.030 6) 6) 6) 1,7) - -
L450 / X65 0,265) - 1,455) 0.030 0.030 6) 6) 6) 1,7) - -
L485 / X70 0,265) - 1,655) 0.030 0.030 6) 6) 6) 1,7) - -
L245N / BN 0.24 0.40 1.20 0.025 0.015 3) 3) 0.04 7,9) 0.43 0.25
L290N / X42N 0.24 0.40 1.20 0.025 0.015 0.06 0.05 0.04 7,9) 0.43 0.25
L320N / X46N 0.24 0.40 1.40 0.025 0.015 0.07 0.05 0.04 4,7,9) 0.43 0.25
L360N / X52N 0.24 0.45 1.40 0.025 0.015 0.10 0.05 0.04 4,7,9) 0.43 0.25
L390N / X56N 0.24 0.45 1.40 0.025 0.015 0,105) 0.05 0.04 4,7,9) 0.43 0.25
L415N / X60N 0,245) 0,455) 1,405) 0.025 0.015 0,105) 0,055) 0,045) 6,7,8) as agreed
L245M / BM 0.22 0.45 1.20 0.025 0.015 0.05 0.05 0.04 7,9) 0.43 0.25
L290M / X42M 0.22 0.45 1.30 0.025 0.015 0.05 0.05 0.04 7,9) 0.43 0.25
L320M / X46M 0.22 0.45 1.30 0.025 0.015 0.05 0.05 0.04 7,9) 0.43 0.25
L360M / X52M 0.22 0.45 1.40 0.025 0.015 4) 4) 4) 7,9) 0.43 0.25
L390M / X56M 0.22 0.45 1.40 0.025 0.015 4) 4) 4) 7,9) 0.43 0.25
L415M / X60M 0,125) 0,455) 1,605) 0.025 0.015 6) 6) 6) 7,8) 0.43 0.25
L450M / X65M 0,125) 0,455) 1,605) 0.025 0.015 6) 6) 6) 7,8) 0.43 0.25
L485M / X70M 0,125) 0,455) 1,705) 0.025 0.015 6) 6) 6) 7,8) 0.43 0.25
L415MS / X60MS 0.10 0.45 1.45 0.020 0,00217) 0.08 0.06 0.06 4,11,12,13) - 0.21
L450MS / X65MS 0.10 0.45 1.60 0.020 0,00217) 0.10 0.06 0.06 4,11,12,13,15) - 0.22
L245NE / BNE 0.18 0.40 1.20 0.025 0.015 - - - 14) 0.42 0.25
L290NE / X42NE 0.19 0.40 1.20 0.025 0.015 0.06 0.05 0.04 14) 0.42 0.25
L360NE / X52NE 0.22 0.45 1.40 0.025 0.015 0.10 0.05 0.04 4,14) 0.43 0.25
L415NE / X60NE 0.23 0,455) 1,405) 0.025 0.015 0,105) 0,055) 0,045) 4,13,14) as agreed
L245ME / BME 0.18 0.45 1.20 0.025 0.015 0.05 0.05 - 14) 0.40 0.25
L290ME / X42ME 0.18 0.45 1.30 0.025 0.015 0.05 0.05 - 14) 0.40 0.25
L360ME / X52ME 0.18 0.45 1.40 0.025 0.015 0.06 0.06 0.05 14) 0.41 0.25
L415ME / X60ME 0,125) 0.45 1.60 0.025 0.015 0.09 0,0810) 0.07 4,16) 0.42 0.25
L450ME / X65ME 0,125) 0.45 1.60 0.025 0.015 0.09 0,0810) 0.07 4,16) 0.43 0.25
L485ME / X70ME 0,125) 0.45 1.70 0.025 0.015 0.11 0,0810) 0.07 4,16) 0.43 0.25
  1. Cu ≤ 0,50 %, Ni ≤ 0,50 %, Cr ≤ 0,50 %, Mo ≤ 0,15 %
  2. For each reduction of 0,01 % below the established maximum for C, an increase of 0,05 % Mn is allowed, up to a maximum of: 1,65 % for the varieties ≥ L245 or B, but ≤ L360 or X52; 1,75 % for varieties > L360 or X52 but < L485 or X70; 2,00 % for varieties ≥ L485 or X70, but ≤ L555 or X80; 2,20 % for varieties > L555 or X80; for sour gas application (S) and natural gas pipeline (E), a maximum increase of 0,20 % above the corresponding maximum value of Mn is allowed.
  3. Unless otherwise agreed, Nb + V ≤ 0.06 %
  4. Nb + V + Ti ≤ 0,15 %
  5. Unless otherwise agreed.
  6. Unless otherwise agreed, Nb + V + Ti ≤ 0,15 %.
  7. No intentional additions of B are allowed and the remaining B must be ≤ 0.001 %.
  8. Unless otherwise agreed: Cu ≤ 0.50 %, Ni ≤ 0.50 %, Cr ≤ 0.50 % and Mo ≤ 0.50 %.
  9. Unless otherwise agreed: Cu ≤ 0,50 %, Ni ≤ 0,30 %, Cr ≤ 0,30 % und Mo ≤ 0,15 %.
  10. If higher Nb limits are used, the following equation must be satisfied: Nb + C ≤ 0.20 %.
  11. Algesamt ≤ 0,060 %; N ≤ 0,012 %; Al/N ≥ 2:1 (not applicable to Ti-calmed or Ti-treated steel); Cu ≤ 0,35 % (acc. to Agreement: Cu ≤ 0.10 %); Ni ≤ 0.30 %; Cr ≤ 0.30 %; Mo ≤ 0.15 %; B ≤ 0.0005 %.
  12. For welded pipes where Ca is intentionally added, this shall apply unless otherwise agreed: Ca/S ≥ 1.5, when S > 0,001 5 %. For seamless and welded pipes, the Ca content ≤ must be 0.006 %.
  13. By agreement Mo ≤ 0,35 %.
  14. 0,015 % ≤ Altotal ≤ 0,060 %; N ≤ 0,012 %; Al/N ≥ 2/1, Cu ≤ 0,25 %; Ni ≤ 0,30 %; Cr ≤ 0,30 %; Mo ≤ 0,10 %
  15. By agreement Cr ≤ 0,45 %.
  16. 0,015 % ≤ Altotal ≤ 0,060 %; N ≤ 0,012 %; Al/N ≥ 2/1, Cu ≤ 0,50 %; Ni ≤ 0,50 %; Cr ≤ 0,30 %; Mo ≤ 0,35 %
  17. The maximum content for S may be increased to 0,006 %. In the case of higher S, lower ratios of Ca/S may be agreed.

Mechanical properties1) according to pipe standards (EN 10208-2 and API 5 L)

Grade Yield strength Rt 0,5 Min. tensile strength Rm Min. elongation A5 Min. notch impact energy at 0°C Drop weight tear test min. amount
of fracture by shear stress at 0°C
MPa MPa % J %
EN 10208–2
L245NB 245 - 440 415 22 - 2)
L245MB 245 - 440 415 22 - 2)
L290NB 290 - 440 415 21 - 2)
L290MB 290 - 440 415 21 - 2)
L360NB 360 - 510 460 20 - 2)
L360MB 360 - 510 460 20 - 2)
L415MB 415 - 565 520 18 - 853)
L450MB 450 - 570 535 18 - 853)
L485MB 485 - 605 570 18 - 853)
API 5 L
Gr. B min. 245 415 29,54) 685) 605)
X 42 min. 290 415 29,54) 685) 605)
X 46 min. 320 435 28,54) 685) 605)
X 52 min. 360 460 27,04) 685) 605)
X 56 min. 390 490 25,54) 685) 605)
X 60 min. 415 520 24,04) 685) 605)
X 65 min. 450 535 23,54) 685) 605)
X 70 min 485 570 22,54) 685) 605)
  1. Values for pipe circumference tests
  2. Not applicable
  3. Mean value of two tests
  4. Elongation on a 2-inch test specimen for a coil thickness of ≥ 8.42 mm, for smaller thicknesses correspondingly lower minimum elongations apply
  5. Mean value of all heats

Drop weight test

According to prior agreement, the steel grades can be supplied as per DIN EN 10274, while also ensuring DWTT values.

Hot-forming properties

The normalized rolled steel grades L245NB - L415NB are suitable for hot forming. Hot forming of the thermomechanical rolled steel grades L245MB - L485MB above 580°C may cause a decrease of yield point and tensile strength and should therefore be avoided. If the pipes are intended for manufacturing inductive bends, this has to be coordinated with the producer.

Heat treatment

Normalized and stress relief annealing of the normalized rolled steel grades is possible. Since normalized and stress relief annealing above 580 °C of the thermomechanical rolled steel grades may cause a decrease of yield point and tensile strength, both heat treatment methods should be avoided.

Welding

Observing the general technical directions, the steel is weldable by hand as well as mechanically according to all electric processes. A preheating of the steel for welding purposes is not necessary if normal laying conditions prevail. It has to be taken into account that the behaviour of this steel during welding and thereafter depends not only on the material but also on the conditions of welding the pipeline and may thus be impaired.

The filler metals to be used for these tensile strengths are welding rods and electrodes approved accordingly.

Condition of delivery, scope of testing and certificate

Delivery and test can be agreed to be made similar to EN 10208-2 and API 5 L. Especially at spiral-welded pipes, the customer has to consider the Bauschinger effect when ordering hot-rolled coils. By agreement, hot-rolled steels of a thickness of up to 24mm can be delivered.

Certificates according to DIN EN 10204 can be supplied as follows: IT, DUN, FAX, e-mail, paper.