Quard 450: High-Performance Martensitic Abrasion-Resistant Steel

Quard 450 is a martensitic abrasion resistant steel, with an average hardness of 450 HBW. The steel offers very high resistance to abrasive wear and impact granting a longer service life. The combination of very good cold forming properties and excellent weldability makes Quard 450 an optimal choice for most wear applications.

Properties

General

Property	Value	Comment
Carbon equivalent (CET)	0.3 [-]	for thickness 3.2-7.99 mm
	0.32 [-]	for thickness 8-20 mm
	0.37 [-]	for thickness 20.01-40 mm
	0.4 [-]	for thickness 40.01-64 mm
Carbon equivalent (CEV)	0.41 [-]	for thickness 3.2-20 mm
	0.56 [-]	for thickness 20.01-40 mm
	0.64 [-]	for thickness 40.01-64 mm
Carbon equivalent note	CEV = C+Mn/6+ (Ni+Cu)/15+ (Cr+Mo+V)/5 and CET = C+(Mn+Mo)/10+Ni/40 +(Cr+Cu)/20

Dimension

Property	Value
Width	1500 - 3100 mm

Mechanical

Property	Temperature	Value	Testing Standard	Comment
Charpy impact energy, V-notch	-40 °C	45 J
Elongation		10 %		A5
Hardness, HBW		420 - 480 [-]	EN ISO 6506-1	1-2 mm below the plate surface once per heat and 40 tonnes
Tensile strength		1400 MPa		Transverse
Yield strength		1250 MPa

Chemical properties

Property	Value	Comment
Boron	0.005 %	for thickness 3.2-64 mm
Carbon	0.2 - 0.23 %	for thickness 3.2-64 mm
Chromium	0.2 - 1.3 %	for thickness 3.2-64 mm
Manganese	1.4 - 1.6 %	for thickness 3.2-64 mm
Molybdenum	0.25 - 0.5 %	for thickness 3.2-64 mm
Nickel	0.1 - 0.5 %	for thickness 3.2-64 mm
Phosphorus	0.025 %	for thickness 3.2-64 mm
Silicon	0.6 %	for thickness 3.2-64 mm
Sulfur	0.01 %	for thickness 3.2-64 mm

Technological properties

Property

Application areas

Quard 450 is mainly recommended for the following applications:

on road tipper and dumper bodies

cement drum mixer barrels,

refuse haulers, scrap containers

buckets, knives

feeders, skips, screw conveyors

mining and earthmoving machinery

Chemical composition

The steel is grain refined.

Cold Forming

Quard 450 is very well suited for cold forming operations. The minimum recommended R/t ratio when bending of Quard 450 is given in the table below:

Thickness (mm)	Transverse to rolling (R/t)	Longitudinal to rolling (R/t)	Trans. Width (W/t)	Long. Width (W/t)
t < 8.0	3.5	4.0	10	10
8 ≤ t < 20	4.0	5.0	10	12
t ≥ 20	5.0	6.0	12	14

R = Recommended punch radius (mm), t = Plate thickness (mm) , W – Die opening width (mm) (bending angle ≤ 90°)

Due to the homogeneous properties and narrow thickness tolerances of Quard 450, variations in springback is kept a a low level. Grinding of flame cut or a sheared edge in the bending area is recommended to further prevent cracking during bending.

Delivery condtion

Our Quard plates are supplied as standard in the shotblasted and primed condition. In order to maintain a good weldability and laser cutting performance, a low zinc silicate primer is applied. Plates can also be delivered unpainted.

Heat Treatment

Quard 450 receives its properties by quenching and when applicable by subsequent tempering. The properties of the delivery condition can not be retained after exposure at service or preheating temperatures above 250 °C. Quard 450 is not intended for any further heat treatment.

Machining

Quard 450 offers good machinability with HSS and HSS-Co alloyed drills. The feed rate and cutting speed have to be adjusted to the high hardness of the material. Face milling, counter boring and countersinking are best performed using tools with replaceable cemented carbide inserts.

Other

Quard 450 is delivered with a unique combination of excellent flatness, tight thickness tolerances and superior surface finish.

Feature	Norm
FLATNESS	EN 10029: Class N (standard) & Class S
THICKNESS tolerance	-meets and exceeds EN 10029 Class A -tighter tolerances upon request
Shape, length, width tolerances	meets EN 10029
SURFACE properties	exceeds the usual market standards,EN 10163-2 Class B3

Testings

Ultrasonic testing (UT), is applied to secure the plate from discontinuities like inclusions, cracks and porosity. In thickness from 8 mm and up, all plates are UT tested and controlled against class S2, E2, according to EN 10160.

Thermal cutting and welding

Plasma and flame cutting can be performed without the need for preheating in thicknesses up to 40 mm, provided the ambient temperature is above 0 °C. Subsequent to cutting, let the cut parts slowly cool down to room temperature. A slow cooling rate will reduce the risk of cut edge cracking (never accelerate the cooling of the parts).

Welding

Quard 450 has a very good weldability, granted by the low carbon equivalent of the steel. It can be welded using any of the conventional welding methods, both as manual or automatic.

Welding of Quard 450 is recommended to be performed at ambient temperature not lower than +5°C. Subsequent to welding, let the welded parts slowly cool down to room temperature (never accelerate the cooling process of the weld).

If welding using a heat input of 1.7 kJ/mm, preheating is not required in single plate thickness up to 20 mm. The interpass temperature used should not exceed 225 °C.

Soft weld consumables, giving low hydrogen weld deposits (<= 5 ml/100g), are recommended. The consumable strength should be as soft as the design and wear mode allows.

In general, the welding recommendation of Quard 450 should be in the accordance to EN-1011.

Quard 400: High-Performance Martensitic Abrasion-Resistant Steel Quard 500: High-Performance Martensitic Abrasion-Resistant Steel

Metal