Overview
Serica is available on formable and high-strength steels for exposed applications in widths up to 1850mm.
Surface aspects
Zinc layer
|
Coating weight double sided |
Coating thickness single sided |
Pure Zinc (GI) |
90-140 g/m2 |
7-10 μm |
Roughness
Ra (cut-off 2.5mm) |
0.9-1.4 μm |
Peak count
Waviness Wsa(1-5) after forming*
Serica 35 |
< 0.35 μm |
Serica 32 |
< 0.32 μm |
Serica 29 |
< 0.29 μm |
* At a biaxial strain of 5%
Surface quality
Serica is the highest possible surface quality for hot-dip galvanised steels as it provides an optimisation of the long wave surface structures of the steel in addition to the controlled quality level that is provided by the MC quality standard.
Oiling
The material surface is oiled with preservative oil. The amount of supplied oil ranges from 0.5 g/m2 to 2.0 g/m2. Other types of oils or different levels are available upon request.
Relationship with standards
Grade availability for Serica 35, 32 and 29
Serica 35 and Serica 32 are available on all hot-dip galvanised forming and bake hardening steels and are in development for the interstitial free grades. Serica 29 is currently available on BH180 and under development for BH220 and BH260.
Product group |
Grade |
EN 10346:2015 |
VDA 239-100 |
Steel for forming |
DX54 |
DX54D |
CR3 |
DX56 |
DX56D |
CR4 |
DX57 |
DX57D |
CR5 |
Phosphorus alloyed interstitial free |
IF180 |
HX180YD |
CR180IF |
IF220 |
HX220YD |
CR210IF |
IF260 |
HX260YD |
CR240IF |
Bake hardening |
BH180* |
HX180BD* |
CR180BH* |
BH220 |
HX220BD |
CR220BH |
BH260 |
HX260BD |
CR260BH |
Items not shown in bold are grades in development
* Available in Serica 29
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Properties
Mechanical properties
Grade | Yield strength1 | Min. | Tensile strength | Min. elongation after | Min. r-value | Min. n-value |
ReL | BH2 | Rm | fracture A | r90 | n90 |
N/mm2 | N/mm2 | N/mm2 | % | | |
BH180 |
180 - 240 |
35 |
290 - 360 |
34 |
1.5 |
0.16 |
BH220 |
220 - 280 |
35 |
320 - 400 |
32 |
1.2 |
0.15 |
BH260 |
260 - 320 |
35 |
360 - 440 |
28 |
- |
- |
1. Lower yield strength or 0.2% proof stress applies.
BH2 refers to the increase of 0.2% proof stress after heating (bake hardening). Not applicable for hot-rolled substrate.
The values of the yield strength are: those of the 0.2% yield strength for products with no definite yield point; the lower yield strength ReL for the other products.
Grade | Yield | Tensile strength Rm | Min. elongation after fracture A 2 | Min. | Min. |
strength 2 ReL | | r-value r90 | n-value n90 |
N/mm2 | N/mm² | % | | |
DX54 |
120 - 220 |
260 - 350 |
36 |
1.6 |
0.18 |
DX56 |
120 - 180 |
260 - 350 |
39 |
1.9 |
0.21 |
DX57 |
120 - 170 |
260 - 350 |
41 |
2.1 |
0.22 |
1. If the yield point is not pronounced, the values apply to the 0.2% - proof strength Rp0.2 ; if the yield strength is pronounced, the values apply to the lower yield point ReL.
2. Decreased minimum elongation values apply for product thickness t ≤ 0.50mm (minus 4 units) and for 0.50mm ≤ t ≤ 0.70mm (minus 2 units).
Chemical composition
Tata Steel supplies the following cast analysis with maximum values in weight percentages:
Grade | C | Mn | Si | P | S | Altot | Ti | Nb |
| Max. | Max. | Max. | Max. | Max. | | Max. | Max. |
BH180 |
0.1 |
0.7 |
0.5 |
0.06 |
0.025 |
≤ 0.1 |
0.12 |
0.09 |
BH220 |
0.1 |
0.7 |
0.5 |
0.08 |
0.025 |
≤ 0.1 |
0.12 |
0.09 |
BH260 |
0.1 |
0.8 |
0.5 |
0.1 |
0.025 |
≤ 0.1 |
0.12 |
0.09 |
Grade | C | Mn | P | S | Al | N | Ti |
|
Max. |
Max. |
Max. |
Max. |
Min. |
Max. |
Max. |
DX54 |
0.12 |
0.6 |
0.1 |
0.045 |
- |
- |
0.3 |
DX56 |
0.12 |
0.6 |
0.1 |
0.045 |
- |
- |
0.3 |
DX57 |
0.01 |
0.2 |
0.020 |
0.020 |
0.01 |
- |
0.2 |
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Dimensions
Dimensional capability
Galvanised (GI) products
Dimensions in mm.
From - up to | DX56 | BH180 | Future capability |
(all grades) |
0.45 - 0.62 |
- |
1230 |
1230 |
0.62 - 0.65 |
- |
1587 |
1850 |
0.65 - 0.70 |
1650 |
1650 |
1887 |
0.70 - 0.75 |
1650 |
1750 |
1950 |
0.75 - 1.0 |
1650 |
1850 |
1950 |
The minimum width is 900 mm.
Tolerances
Tolerances comply with standard EN 10143:2006 (click here).
Tighter tolerances are available on request.
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