A22    
  Ultra High Strength Low Alloy steels   Last update: 2011-4-5

Using these steel grades makes it possible to build longer/higher booms for cranes and aerial platforms.

 

Properties
   

These low alloy steel grades complete the ArcelorMittal range of HSLA grades (data sheet A20) and offer exceptionally high yield strength values. They have a fine grain structure, a low carbon content for improved weldability, and controlled internal purity.

 

Advantages
   

Weight reduction

 

The grades in this data sheet combine outstanding mechanical properties (very high strength, fatigue resistance and toughness) with good formability and weldability. The guaranteed high yield strength of these grades makes it possible to achieve substantial weight reduction through thickness reduction, whilst maintaining overall performance and safety. These steel grades are therefore frequently used to replace structural steel grades where weight reduction is required.

 

Thickness reduction brings additional savings when processing the material, since it is easier to weld, and reduces transport costs. Further savings are also achieved in service, in the form of lower energy consumption, improved mechanical performance, safety etc.

 

Abrasion/wear resistance

 

In some applications (conveying devices, earth-moving or transportation vehicles etc), wear can result from the action of abrasive substances on the steel surface. This is a complex physical phenomenon, which depends not only on the abrasive material itself, but also on the way abrasion occurs (pressure, load, impact etc).

Compared with standard structural steel grades, Ultra High Strength Low Alloy steel grades allow a significant improvement in wear resistance. In many instances, they can be more economical and easier to process than steel grades specifically designed for wear resistance.

 

Applications
   

Their very high yield strength contributes to a solution that increases the payload capacity and gives higher strength structures.

Typical applications include telescopic cranes, tippers, truck and trailer manufacturing industries, where the emphasis is on strength and weight reduction potential.

 

Recommendations for use
   

Laser cutting

These grades are suitable for oxygen, plasma and laser cutting.

 

Coil extremity scrapping with S700MC AM FCE

Thicknesses less than or equal to 7 mm do not require the coil extremity to be scrapped, since the steel mechanical properties are guaranteed over the whole length of the coil. For thicknesses over 7 mm, 5 m should be scrapped at each extremity.

 

Estimation of the possible thickness reduction

When switching from grade 1 (with a low yield strength) to grade 2 (proposed in this data sheet), an estimation of the thickness reduction achievable is given by the following formula:

t2 = t1 (Re1/Re2)½

where t = thickness            Re = yield strength   

Please note that other issues, such as fatigue resistance, need to be checked before doing any thickness reduction.

 

Surface quality
   

These grades are available in "A - Unexposed" quality only.

 

Weldability
   

Due to their low carbon equivalent value (< 0.42%), these ArcelorMittal grades do not need to be pre- or post-heated when welding. Moreover, these grades are totally insensitive to cold cracking and are suitable for all types of arc welding.

 

Recommended wires/fluxes for S700MC AM FCE are listed in the table below:

SupplierSMAWGMAWFCAWSAW
EsabOK 75.75OK Autrod 13.29OK Tubrod 14.03OK Autrod 13.43OK Flux 10.62
FilarcFilarc 118 Filarc PZ 6148  
LincolnConarc 80LNM MoNiVaOutershield 690-HLNS 168P230
Conarc 85 Outershield MC-100LA 100Lincolnweld 8500
OerlikonTenacito 80 CLCarbofil NiMoCrFluxofil 42OE-S3 NiMoCrOP 121TT
Tenax 118MCarbofil MnNiMoCitoflux M07Fluxocord 42
SAF-FROSafer ND 80Filcord 100Steelcored 42  
  Safdual 270  
ThyssenSH Ni2 K100Union NiMoCr Union S3 NiMoCrUV 421TT

 

  • In order to reduce the softening effect in the heat-affected zone (HAZ), it is recommended that the welding energy should be limited to 2 kJ/cm per millimetre of thickness.
  • For S700MC AM FCE grade, softening of the HAZ can be avoided by keeping the calorific input under the values given in the figure below. 

 

 

  • The impact resistance of the welded area of S700MC AM FCE steel (measured using the KCV test) is superior to the minimum requirements of the European standards EN 288 and EN 10149 relating to the base metal (40 J at -20°C or 27 J at -40°C).
  • Heat treatment of the weld might reduce its strength. It is therefore strongly recommended that you contact ArcelorMittal prior to performing any heat treatment, to define the settings suitable for welded S700MC AM FCE.

 

Fatigue resistance
   

The fine grain size and low sulphur content improve the fatigue resistance of the steel. Fatigue performance is measured by uniaxial tests at different stress levels. These values are used to draw the Wöhler curve and determine the Dan Vang factor of the steel.

 

The Wöhler curve of S700MC AM FCE is shown below:

This shows that S700MC AM FCE can withstand a maximum stress of 590 MPa for up to 2,000,000 cycles (with R = 0.1).

However, it should be noted that it is advisable – as with most materials – to keep welds away from highly stressed zones, particularly in the case of dynamic loading, since the Wöhler curve for welds depends on welding conditions.

 

Brand correspondence
   
 EN 10149-2:1995NF A 36-203:1992BS 1449/1SEW 92USA ASTMOld brand names
S600MC EN 10149-2S600MC  QstE 600TM  
S600MC AM FCES600MC  QstE 600TMA 514 
S650MC EN 10149-2S650MC  QstE 650TM  
S700MC EN 10149-2S700MC(E690D) QstE 690TM  
S700MC AM FCES700MC(E690D)75F70QstE 690TMA 514Soldur 700
() Closest grade as no fully equivalent grade exists.


 

Dimensions
   

S600MC - Mill finish
Thickness (mm)Min widthS600MC EN 10149-2, S600MC AM FCE
Max width
2.00 ≤ th < 2.208001100
2.20 ≤ th < 2.351170
2.35 ≤ th < 2.501200
2.50 ≤ th < 3.001250
3.00 ≤ th < 3.501340
3.50 ≤ th < 4.001440
4.00 ≤ th < 4.501540
4.50 ≤ th < 5.501630
5.50 ≤ th < 6.001830
6.00 ≤ th < 8.502135
8.50 ≤ th < 9.501980
9.50 ≤ th < 10.001930

S600MC - Pickled

Please contact us.


S650MC - S700MC - Mill finish
Thickness (mm)Min widthS650MC EN 10149-2S700MC EN 10149-2, S700MC AM FCE
Max widthMax width
2.00 ≤ th < 2.50800-1250
2.50 ≤ th < 2.801100
2.80 ≤ th < 3.001250
3.00 ≤ th < 3.5013001290
3.50 ≤ th < 4.0015001390
4.00 ≤ th < 6.001540
6.00 ≤ th < 6.301680
6.30 ≤ th < 8.001830
8.00 ≤ th < 10.001280

S650MC - S700MC - Pickled

Please contact us.




 

Mechanical properties
   

Toughness

The fine grain size and low sulphur and carbon content of the S600MC AM FCE and S700MC AM FCE grades improve steel toughness.

 

Bending

The minimum 180° bending radius of S700MC AM FCE can vary according to the edge quality of the sheet:

  • On milled edges and good-quality plasma or laser cut edges, bending can be performed with a minimum mandrel diameter of 1.8 times the sheet thickness
  • For cut edges (sheared or slit), depending on the care exercised in shearing/cutting, a bend with a mandrel diameter of 1.8 times the thickness is achievable, but fracture of the outside surface of the bend edge may occur


 
Notes
Direction
Thickness (mm)
Re (MPa)
Rm (MPa)
A80 (%)
A 5.65√So (%)
Bending ratio (th)
KV -20°C (J)
KV -40°C (J)
S600MC EN 10149-2 L2 - 3≥ 600650 - 820≥ 11----
3 - 10-≥ 13
T2 - 10----≥ 1.5--
S600MC AM FCE L2 - 3≥ 600650 - 820≥ 11----
3 - 6-≥ 13
6 - 10≥ 40
T2 - 10----≥ 1.5--
S650MC EN 10149-2 L2 - 3≥ 650700 - 880≥ 10----
3 - 8-≥ 12
8 - 10≥ 630
T2 - 10----2 - 0--
S700MC EN 10149-2 L2 - 3≥ 700750 - 950≥ 10----
3 - 8-≥ 12
8 - 10≥ 680
T2 - 10----≥ 2--
S700MC AM FCE1L2 - 3≥ 700750 - 910≥ 10----
3 - 6-≥ 14
6 - 8≥ 40≥ 27
8 - 10-
T2 - 3≥ 720760 - 910≥ 10-≥ 1.8--
3 - 10≥ 730-≥ 12
Values in bold: tighter than the standard
1. After prior agreement


 

Chemical composition
   

 
C (%)
Mn (%)
P (%)
S (%)
Si (%)
Al (%)
Mo (%)
Nb (%)
V (%)
Ti (%)
B (%)
Galvanisation
S600MC EN 10149-2 ≤ 0.120 ≤ 1.90 ≤ 0.025 ≤ 0.015 ≤ 0.50 ≥ 0.015 ≤ 0.50 ≤ 0.090 ≤ 0.200 ≤ 0.220 ≤ 0.0050 -
S600MC AM FCE ≤ 0.120 ≤ 1.90 ≤ 0.025 ≤ 0.015 0.03 ≥ 0.015 ≤ 0.50 ≤ 0.090 ≤ 0.200 ≤ 0.220 ≤ 0.0050 Class 1
S650MC EN 10149-2 ≤ 0.120 ≤ 2.00 ≤ 0.025 ≤ 0.015 ≤ 0.60 ≥ 0.015 ≤ 0.50 ≤ 0.090 ≤ 0.200 ≤ 0.220 ≤ 0.0050 -
S700MC EN 10149-2 ≤ 0.120 ≤ 2.10 ≤ 0.025 ≤ 0.015 ≤ 0.60 ≥ 0.015 ≤ 0.50 ≤ 0.090 ≤ 0.200 ≤ 0.220 ≤ 0.0050 -
S700MC AM FCE 0.100 ≤ 2.10 ≤ 0.025 0.005 0.15 - 0.25 ≥ 0.015 ≤ 0.50 ≤ 0.090 ≤ 0.200 0.150 ≤ 0.0050 Class 3
Values in bold: tighter than the standard

The above chemical properties are based on cast analysis data.
The total Nb, V and Ti content should not exceed 0.22%.



   
For commercial information (quotations, deliveries, product availability):

For technical questions about these products: fce.technical.assistance@arcelormittal.com
For researchers: click here


All details provided in the ArcelorMittal Flat Carbon Europe S.A. catalogue are for information purposes only. ArcelorMittal Flat Carbon Europe S.A. reserves the right to change its product range at any time without prior notice.