Steel structures – Laboratory

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1. STEEL GRADES AND QUALITIES

The European standard EN 10020 classifies steel grades into:
 non-alloy and alloy steels by chemical composition
 quality classes defined by main property or application characteristics for non-alloy and
alloy steels.

1.1 NON-ALLOY STEELS

Steel grades can be classified into the following quality classes:

 Non-alloy base steels

 Non-alloy quality steels
 Non-alloy special steels

Hot-Rolled Products in Non-Alloy Steels for General Structural Applications to EN 10025

This standard specifies the requirements for long products (such as sections and bars) and flat
products (such as plate, sheet and strip) of hot-rolled non-alloy general purpose (base) and quality
steels. These steels are intended for use in welded, bolted and riveted structures for service at
ambient temperature.

The designation consists of:

 The number of the European standard (EN 10025).

 The symbol FS.
 The indication of the minimum specified yield strength for thicknesses £ 16mm expressed in
N/mm2.
 The quality designation in respect of weldability and resistance to brittle fracture JR, J0, J2
and K2.
 If applicable, an indication of the deoxidation method (G1 or G2).
 If applicable, the letter symbolic for the suitability for cold flanging, cold rolling or cold
drawing.
 If applicable the indication + N when the products have normalizing rolling.

1.2 ALLOY STEELS

A disadvantage of non-alloyed structural steels is their corrosion tendency under atmospheric

conditions. They usually have to be coated or painted in order to protect the surface against
moisture, oxygen and aggressive chemicals. To reduce rust formation and thus avoid painting,
weathering steels have been developed. Weathering steels belong to a family of atmospheric
corrosion resistant low alloy steels intended for applications requiring long service life and low
maintenance costs. These steels are produced by the addition of small amounts of alloying elements.
The principal steel grades of EN 10 155 are:

S 235J0W; S 235J2W; S 355J0WP; S 355J2WP; S 355J0W;

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1.3 COMPARISON BETWEEN STEEL GRADES

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1.4 STEEL DUCTILITY

The qualitative results of the impact test can be used to determine the ductility of a material. If
the material breaks on a flat plane, the fracture was brittle, and if the material breaks with jagged
edges or shear lips, then the fracture was ductile. Usually a material does not break in just one way
or the other, and thus comparing the jagged to flat surface areas of the fracture will give an estimate
of the percentage of ductile and brittle fracture.
The quantitative result of the impact tests the energy needed to fracture a material and can be
used to measure the toughness of the material. There is a connection to the yield strength but it
cannot be expressed by a standard formula. Also, the strain rate may be studied and analyzed for its
effect on fracture.
The ductile-brittle transition temperature (DBTT) may be derived from the temperature where
the energy needed to fracture the material drastically changes. However, in practice there is no
sharp transition and it is difficult to obtain a precise transition temperature (it is really a transition
region). An exact DBTT may be empirically derived in many ways: a specific absorbed energy,
change in aspect of fracture (such as 50% of the area is cleavage).

Charpy test machine

The Charpy impact test, also known as the Charpy V-notch test, is a standardized high strain-
rate test which determines the amount of energy absorbed by a material during fracture. This
absorbed energy is a measure of a given material's notch toughness and acts as a tool to study
temperature-dependent ductile-brittle transition. It is widely applied in industry, since it is easy to
prepare and conduct and results can be obtained quickly and cheaply. A disadvantage is that some
results are only comparative
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Charpy test results

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2. STEEL PROFILES
According to production of steel profiles we have:
A) Hot Rolled Steel Profiles
Structural shape rolling uses profile rolling techniques where the workpiece is passed through a
series of flatteners. The most common method uses 3 rollers; the bending is controlled by
varying the distance between the rollers.

B) Cold Rolling steel profiles

- Roll forming is a metal fabrication process that utilizes sheet metal in coil form where the
material is progressively shaped as it passes through a series of roller dies for cold rolling.

- In press brake forming, a work piece is positioned over the die block and the die block presses the
sheet to form a shape

C) Welded profiles
- Welded profiles are received by welding together single metal sheets or hot rolled profiles with
oneself

D) Cast profiles
- Steel castings are formed by pouring molten metal into a mould containing a cavity which has the
desired shape of the component.
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2.1 HOT ROLLED PROFILES

Range of the length of Drawing

No Profile Cross - section production the profile symbol Remarks
[mm] [m]

Flat bar s=20150 150 x 12 Rolled in

g
1 acc. to g=655 <9 550 one
EN 10058: 2003 direction
s

Universal plate g s=160700 12 x 150 Rolled in

2 acc. to g=640 514 550 one
EN 10051:2011 direction
s

Metal plate s=1000 518 pl. 18 x 200 Rolled in

g
3 acc. to 3600 550 two
EN 10051:2011 g=3140 directions
s

I sections Taper flange

4 acc. to h=80600 313 (15) I200
EN 10163- h I200p
3:2004

I sections Parallel
5 acc. to h=80600 415 IPE 200 flange
EN 10024:2004 h or
h
I200 PE

If h≤300:
H sections bf=h
6 HEB h=1001000 415 HEB200
acc. to h
EN 53-62

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Range of the length of Drawing

No Profile Cross - section production the profile symbol Remarks
[mm] [m]

H sections
7 HEA H=100 415 HEA 200 to HEA300
acc. to h 1000 h/bf  0.95
EN 53-62

H sections he has very

8 HEM S=100 415 HEM 240 thick flange
acc. to h 1000
EN 53-62 h

Channels some with

9 acc. to h h=35300 315 C140 thinner web
EN-10279:2000 and some
with parallel
flanges

Equal leg angles a=20200 L60x60x5

10 acc. to t=320 315 or
EN-10056- a t L60x5
1:1998
a

Unequal leg a=30100 usually

11 angles b=45200 315 L90x60x8 b/a=1.5
a t
acc. to t=412
EN-10056-
b
1:1998
Z -sections
h=60, 80
12 acc. to and 100 312 Z100
PN-65/H-93405

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Range of the length of Drawing

No Profile Cross - section production the profile symbol Remarks
[mm] [m]
Hot finished
hollow sestion D=20508 412
13 acc. to t=2.330
EN-10210:2006 t R108x7.1
Welded steel or
tubes D=5082020 412 Rbs108x7.1 longitudinal
14 acc. to t=2.330 welded
EN-10217:2004 D

Equal flange tees

15 acc. to h=3080 312 T30
EN-10055:1995

Textured steel t=2.510

plate b=1000,1250 610 Bl.żeb.5x200
16 acc to 1500 500

Crane rails:
Rail sections SD65,
17 acc to h=65180 515(30) Train rails:
S60

U sheet pile to strengthen

18 sections the soil at
(e.g. Larsen pile) penetrations
acc. to open method
EN-10249:2000

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2.2 COLD FORMING STEEL PROFILES

Nazwa wyrobu Przekrój Uwagi

Equal and unequal leg Due to a wide assortment in the picture

angles, channels, square only examples of the most typical
hollow sections, shapers were given. Nominally
rectangular hollow permanent thickness of all partition
sections , Z, C and walls and appearing are their distinctive
sigma profiles, feature radius of curvature of also
trapezoidal sheet outside angles.
profiles

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2.3 WELDED PROFILES

symbol cross - section Steel grade appropriation
web flanges
St3SX
St3SY
St3S
IKS St3M
One axis bending
18G2
beams in steel and
18G2A
composite
18G2A structures
h=600÷2000 18G2Acu
IKSH b=200÷500 18G2AV
h/tw  200 St3S 15G2NNb
b/t  25 10HAV3

St3SX
St3SY
column in axial
St3S
and unaxial
St3M
HKS compression
18G2A
h=600÷2000 18G2ACu
tw=8÷12
t=14÷30

St3SX
column in unaxial
St3SY
IPBS compression
St3S
St3M
18G2A
h=300÷700 18G2ACu
b=300
tw=7÷15
t=19÷32

Castellated
beams with
hexagonal
openings

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2.4 CAST PROFOLES

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