450HBW quenched fine grain wear resistant structural steel plate
450HBW QUENCHED WEAR RESISTANT STEEL is a wear resistant steel with
a nominal hardness of 450 HBW in delivery condition ex works.
450HBW QUENCHED WEAR RESISTANT STEEL is preferentially used by the
customers where elevated resistance to wear is required together
with good workability and especially good weldability.
Examples of application: earth moving and loading machines,
dredgers, skip cars, conveying plants, trucks, cutting edges,
knives and breakers, waste elimination and recycling plants.
Product description
Range of application
450HBW QUENCHED WEAR RESISTANT STEEL can be delivered in
thicknesses from 8 mm (1/3 in.) to 100 mm (4 in.), according to the
dimensional program. Other dimensions may be possible on request.
Chemical composition
For the ladle analysis, the following limiting values in % are
applicable, max.:
| C | Si | Mn | P | S |
| 0.25 | 0.70 | 1.60 | 0.025 | 0.010 |
Depending on thickness, the following alloying elements may be used
singly or in combination, max.:
| Mo | Ni | Cu | Cr | V | Nb | B |
| 0.50 | 0.80 | 0.30 | 1.50 | 0.08 | 0.05 | 0.005 |
The steel is fully killed and fine grain treated.
Delivery condition
Controlled water quenched.
Mechanical properties in the delivery condition
Hardness
Brinell surface hardness at room temperature: 420 - 480 HBW
Tensile testing on transverse specimens at room temperature
(indicative values for 20 mm plate thickness)
Tensile strength: 1400 MPa (203 ksi)3
Yield point: 950 MPa (138 ksi)3
Elongation: 11 % (Lo = 5.65·√So)
In spite of their high tensile properties, VANFORGE steels are not
intended for safety relevant components. For this purpose high
strength steels are available.
Charpy-V impact test on longitudinal specimens (indicative values
for 20 mm plate thickness)
Charpy impact energy: 35 J at -20 °C (-4 °F)
Testing
Brinell surface hardness tested once per heat and 40 t.
Identification of plates
Unless otherwise agreed the marking is carried out via steel stamps
with at least the following information:
- steel grade (450HBW QUENCHED WEAR RESISTANT STEEL)
- 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, construction 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
(Welding) and CEN/TR 10347 (Forming) as well as recommendations
regarding job safety in accordance with national rules should be
observed while considering
the higher strength and hardenability.
Cold forming
450HBW QUENCHED WEAR RESISTANT STEEL can be cold formed by bending
in spite of its high hardness and strength. It should be paid
attention to the fact that with increasing yield strength the
required forces for the forming operation also increase, even if
the plate thickness remains unchanged. The spring-back also
increases. In order to avoid the risk of cracking from the edges,
flame cut or sheared edges should be ground in the area that is to
be cold formed. It is also advisable to round the plate edge
slightly on the outside of the bend coming under tension stress
during bending.
During the processing, the necessary safety measures have to be
taken, so that nobody will be exposed to a danger by a possible
fracture of the work piece during the forming process.
The following geometries can usually be achieved by cold forming
without the formation of surface defects
(where t is the plate thickness):
| Minimum bending radius | Minimum die width |
| Transverse direction | 5 t | 14 t |
| Longitudinal direction | 6 t | 16 t |
Hot forming
Since 450HBW QUENCHED WEAR RESISTANT STEEL obtains its hardness by
accelerated cooling from the austenitizing temperature, hot forming
without major hardness loss is only possible if a renewed quenching
treatment is carried out after forming. However, the hardness
achieved through such a treatment may differ from that measured in
the delivery condition. This is due to the fact that the cooling
conditions at the fabricator’s works are generally less
effective than those available during plate production.
The steel can be heated to about 200 °C (390 °F) without any
substantial drop in hardness 250 °C (482 °F) for short period).
Flame cutting and welding
For flame cutting, the following minimum temperatures should be
observed: 50 °C (122 °F) for plate thicknesses up to 26 mm, 100 °C
(212 °F) for plate thicknesses from 26 up to 52 mm, and 125 °C (257
°F) for thicker plates.
For manual arc welding basic coated rods, having a very low
residual moisture should be used (if necessary, drying according to
the instruction of the manufacturer should be carried out).
Additionally the following recommendations are to be considered:
- Under beneficial conditions the steel may be butt welded without
preheat up to a thickness of 15 mm.
- Preheating above 200 °C (390 °F) must however be avoided, because
it could cause a decrease of the hardness (see diagram).
- Weld metals with low yield strength are preferred for tack, root
and filler passes. If welds are exposed to wear, only the final
passes should be welded with consumables producing a hardness
matching the parent plate.
Heat treatment
The following diagram shows the general changes in hardness or
strength values in accordance with the heat treatment temperature:
Machining
450HBW QUENCHED WEAR RESISTANT STEEL can be machined with
HSS-drills and especially with HSS-Co-alloyed drills with a
satisfactory service life if the drill advance and cutting speed
are correspondingly accommodated.
General technical delivery requirements
Unless otherwise agreed, the general technical requirements in
accordance with EN 10021 are applicable.
Tolerances
Unless otherwise agreed, the tolerances are in accordance with EN
10029, with class A for thickness.
Surface quality
Unless otherwise agreed, the provisions in accordance with EN
10163-2, class A2 are applicable.
General note
If special requirements, which are not covered 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
