S460NL normalized fine grain structural steel plate for tank
construction
P460NL is a weldable normalized fine grained steel which is
characterised by a minimum yield
strength of 460 MPa and a minimum tensile strength of 630 MPa.
P460NL is mainly applied for the construction of tanks for the
transport of liquefied gas with road and rail vehicles where the
weight minimisation plays an important role.
Product description
Designation and range of application
P460 can be supplied in two qualities: P460N and P460NL. They are
both modified steels of the type P460 according to EN 10028-3. They
fulfill the requirements of EN 10028-3:2009 (option 5 and footnote
d, Table 4) and can be applied for:
- tank installations in accordance with RID/ADR as well as EN 14025
- pressure vessels in accordance with AD 2000 Merkblatt, EN13445,
CODAP 2005
This material data sheet applies to heavy plates with thicknesses
from 7 to 20 mm.
Production
BOF-converter process and metallurgical ladle treatment; fully
killed, fine grained steel with addition of nitrogen fixing
elements.
Chemical composition in %, max.
| C | Si | Mn | P | S | N | Ni | V | Cr | Cu | Mo |
| 0.22 | 0.10-0.65 | 0.94-1.80 | 0.025 | 0.008 | 0.027 | 0.45 | 0.10-0.21 | 0.35 | 0.25 | 0.13 |
Delivery condition
Normalized, unless otherwise agreed.
An additional tempering in accordance with EN 10028-3:2009 may be
performed.
Mechanical properties in the delivery condition
The testing of the mechanical properties is performed on specimens
in the condition normalized (N) or normalized and tempered (N+T).
Tensile test at ambient temperature – transverse test specimens
Plate thickness [mm] | Minimum Yield Strength ReH (2) [MPa] | Tensile Strength Rm [MPa] | Minimum Elongation A5 % |
| ≤ 20 | 460 | 630 - 725 | 17 |
(2) If no upper yield strength is apparent, the Rp0,2 is relevant
as defined per EN 10028-1 .
Impact test on Charpy-V-transverse test specimens
| Test temperature [°C] | Minimum impact values [J] |
| P460NL | -40 | 27 |
| Option 2 (to be indicated on the order) |
| P460NL | -40 | 45 |
The specified values are minimum values for the average of 3 tests.
No individual value is to be less than 70 % of the specified
minimum. For plate thickness below 11 mm the test can be carried
out on Charpy-V specimens or Charpy-V-type specimens with reduced
width. The minimum impact value will be reduced proportionally to
the reduction of the specimen’s cross section.
Testing
Sampling, testing method and tests are in accordance with EN
10028-1, unless otherwise stipulated or agreed.
The plates can be delivered with inspection certificate 3.1 or 3.2
in accordance with EN 10204. The kind of the inspection certificate
has to be specified on the order.
Identification
Unless otherwise agreed the marking is carried out via low stress
steel stamps with at least the following information:
• steel designation P460NL
• heat number
• number of mother plate and individual plate
• the manufacturer's symbol
• inspector’s sign
Processing
The entire processing and application techniques are of fundamental
importance to the reliability of the products made from this steel.
The user should ensure that his design, calculation and processing
methods are aligned with the material, correspond to the
state-of-the-art that the fabricator has to comply with and are
suitable for the intended use. The customer is responsible for the
selection of the material. The recommendations in accordance with
EN 1011-2 should be observed.
Formability
The plates can be hot or cold formed. Even in case of appropriate
hot forming an additional tempering can be necessary particularly
for thin plates due to the accelerated cooling within the forming
tool.
Flame cutting and welding
The suitability of P460NL for flame cutting and welding has been
proven. The verification of the toughness properties is performed
on welding specimens with basic filler metal and a cooling time
t8/5 in the range between 8 and 25 seconds. In case of high
toughness requirements it may be necessary to reduce the heat input
so that the t8/5 time is below 20 seconds. In any case welding
shall be performed in multi pass technique with flat welding passes
and good grain refinement.
Heat treatment
If stress-relieving treatment is necessary, this is usually
performed on the finished welded vessel. The stress-relieving
treatment should be performed at temperatures between 530 °C to 560
°C, as higher temperatures lead to reduced toughness properties in
the weld. The time-temperature-parameter P in accordance with EN
10028-3 must not exceed the value 16.35 for P460NL. The holding
time should not exceed 150 minutes even for heat treatments in
several cycles. For holding time above 90 minutes the lower limit
of the temperature range should be aimed at. The subsequent cooling
is performed in still air.
The stress-relieving treatment can be omitted if no corrosive media
will be transported in the vessels and if allowed by the applicable
regulations.
Tolerances
Unless otherwise agreed, tolerances are in accordance with EN
10029, with class B for the thickness.
Surface quality
Unless otherwise agreed, the provisions in accordance with class B2
of EN 10163-2 are applicable.
General technical delivery requirements
Unless otherwise agreed, the general technical delivery
requirements in accordance with EN 10021 apply.
General note
If special requirements, which are not listed in this material data
sheet, are to be met by the steel due to its intended use or
processing, these requirements are to be agreed before placing the
order.
Production process
