Creusabro® 4800℗ – Add Corp Steel Solutions

General Information

Better than only hardness, CREUSABRO ® 4800 ℗ offer an exceptional upper wear resistance from + 40 up to 45 % compared with 400 HB, water quenched steel, maintaining in the same time an easier processing aptitude. Thanks to different chemical composition dedicated to each thickness range CREUSABRO ® 4800 ℗implements several metallurgical concepts which are more efficient than simple hardness:

The intentionally limited hardness of CREUSABRO ® 4800 ℗ at delivery condition facilitates in a significant proportion the different processing operations such as: cutting, machining and transformation (bending & rolling).

CREUSABRO ® 4800 ℗ is suitable against all types of abrasion phenomenon like sliding, impact, dry or wet environment, including high temperature (< 450℃ th < 20 mm) and (< 350 ℃ th > 20 mm) in continuous operating condition.

CHEMICAL ANALYSIS

C	S	P	Mn	Ni	Cr	Mo	Ti
<= 0.20	<= 0.005	<=0.018	<= 1.60	~0.20	<=1.90	<=0.40	<=0.20

MECHANICAL PROPERTIES

Hardness (HB)	Yp MPa (ksi)	UTS MPa (ksi)	Elongation %	KCVL -20℃ (J/㎠)	Elasticity Module GPa
370	900	1200	12	45	205

Guaranteed values (as supplied) Hardness 340/400 HB

Cutting processes

CREUSABRO ® 4800 ℗ can be cut with all thermal processes: Oxy-gas, Plasma & Laser. Technical working conditions are close to usual condition used for low carbon & low alloyed steel.
Whatever the thermal cutting process chosen To of plate must be at a minimum workshop of = 10 ℃. In winter period that can signify plates must be stored in the workshop several days before any cutting operation.
High mechanical properties of CREUSABRO ® 4800 ℗ do not allow any mechanical cutting processes such as, shearing or punching operations, for th around 12 mm and up.

Oxy-gas

Type of Gas

Advice for obtaining quality profiled parts

Plate preheating To

Plate thickness (mm)	preheating Temperature (℃)\|*\|
3 - 60	Without preheating
61 - 150	Preheating > 150 ℃

In case of cutting job th > 25 mm, it is imperative not only to adjust cutting parameters (reduce significantly cutting speed), but also to proceed to a pre-heating, measured in between 160 / 180 ℃. Piece and drop off must be covered,up to complete cooling down, in order to limit cracks risk due to oxygas.
Even for th < 25 mm considering ambient To of workshop, it could be necessary to warm up plate with torch or warm up the design on cutting bed without oxygen, before to proceed to final cutting operation.

Other cutting parameters

Supplemental advice

Reduce the cutting speed in angular curve & rounded corner especially for thick thickness.
For cutting of complex shapes, cut internal holes first and after cut the external edges of the piece. Such a sequence results in reduced distortion of the piece and limits the risk of cracking in case of straightening.
For cutting complex designs, speed must be reduced when cutting direction changes, this increases correlatively contact time with flame and then increases the depth of Heat Affected Zone (H.A.Z.).
CREUSABRO ® 4800 ℗ chemical composition contains a significant % of Cr & Mo which are limiting this negative effect, but don't cancel it totally.

Plasma

CREUSABRO ® 4800 ℗ plasma cutting process is more advantageous than oxygen cutting considering the following points:

For plate thickness < 30 mm, cutting time is halved compared with oxy-gas ;
Post deformation is reduced;
For thin plates, there is an absence of slag sticking to cut edges ;
Smaller heat affected zone, enabling arc welding to be carried out directly on the edges after simple edge brush cleaning.

As with flame cutting, a preheating at 150 ℃ is required to cut plate thicknesses higher than 60 mm.

Laser cutting

This solution is particularly adapted for cutting plate.

High precision and conformity of cutting;
No deformation of the piece after cutting;
Insignificant H.A.Z.;
No excess material at root or metal drops underneath;
Direct welding without edge dressing;
Lower heating zones in the case of cutting small pieces.

Operational capacities of current machines allow plates up to 20 mm to be cut.

Shearing

Adjustment

Punching

Punching of CREUSABRO ® 4800 ℗ is possible for plate thickness up to about 12 mm max.

Specific recommendations

Water jet cutting

This cold cutting process is ideal to produce small pieces from plates.
No microstructure change will occur in the thickness and on the edge of the piece. Hardness and consequently wear resistance will remain completely homogeneous throughout the whole piece.
Nevertheless, productivity of water jet remains rather low

Welding

The adjustments of its chemical analysis confer to CREUSABRO ® 4800 ℗ an excellent behaviour against abrasion. Welding, however, requires to take some precautions and to follow particular recommendations.
Cold cracking is the main risk during welding of this type of material.It can occur immediately and up to 72 hours after the end of welding.It may occur by the interaction of three metallurgical parameters:

Creation of a brittle structure (fresh martensite) in the H.A.Z. or in welded metal;
Creation of residual stresses of welding, related on the shrinking of steel during the solidification of the molten metal and also due to the differences in thermal expansions;
Possible hydrogen introduction into the sensitive zone of the weld (H.A.Z., weld metal).