EN-Automotive-Product-Metallic coated-AHSS UHSS-All Grades OverviewTSE
Meeting design demands
Body-in-white design demands affordability and improved crash performance, combined with low weight. Our advanced high-strength steels (AHSS) and ultra high-strength steels (UHSS) help meet those demands and provide good formability.
Tata Steel supports customers in finding the optimum balance between cost, lightweight design potential and performance for specific applications. Total cost of ownership (TCO) concept studies identify and quantify the TCO reduction potential offered by Tata Steel’s advanced steel solutions like HyperForm® for specific automotive applications.
Applications
Applications for our advanced high-strength and ultra high-strength steels include:
- automotive A-, B- and C-pillars
- box girders for chassis
- crash boxes
- crossbeams and cross members
- roofbows
- door and sill reinforcements
- support components
Relationship with standards
Tata Steel offers the following grades:
| Grade | VDA 239-100 | EN 10346:2015 |
|---|---|---|
| Dual-phase | ||
| CR DP600-GI/GA | CR330Y590T-DP-GI/GA | HCT590X+Z/ZF |
| CR DP600-GI HyperForm® | CR330Y590T-DH-GI 1 | - |
| CR DP800-GI/GA | CR440Y780T-DP-GI/GA | HCT780X+Z/ZF |
| CR DP800-GI HyperForm® | CR440Y780T-DH-GI | - |
| CR DP1000LY-GI | CR590Y980T-DP-GI | HCT980X+Z |
| CR DP1000HY-GI | CR700Y980T-DP-GI | HCT980XG+Z |
Please contact us for AHSS with MagiZinc® coating.
1) VDA draft
EN-Automotive-Product-Metallic coated-All Grades Coatings Surface aspectsTSE
Coatings
Three types of metallic coating are available:
- Pure zinc. Galvanised steel (GI) is coated with an almost pure zinc coating (>99% zinc)
- Zinc-iron alloy. Galvannealed steel (GA) is coated with a zinc coating containing approximately 8-12% iron
- MagiZinc Auto. MagiZinc Auto steel (ZM) is coated with a zinc coating containing additional magnesium and aluminium.
Coating weight
Coating | Minimum | Maximum |
|---|---|---|
| Pure zinc (Z) | 90 (6 µm/side) | 600 (42 µm/side) |
| Zinc-iron (ZF) | 90 (6 µm/side) | 140 (10 µm/side) |
| MagiZinc (ZM) | 70 (5 µm/side) | 200 (14 µm/side) |
Coating weight measured in g/m2 double-sided (µm, per side).
Surface condition
Surface condition complies with standard: EN 10346:2015. Galvanised steels are available in surface conditions with minimised spangle MB or MC. Galvannealed steels and MagiZinc Auto are available in surface conditions B or C.
Surface condition B: improved surface, suitable for unexposed parts
With this surface condition, small imperfections such as stretch levelling breaks, skin pass marks, slight scratches, indentations, surface structure, zinc run-off marks and light passivation stains are permissible.
Surface condition C: best quality surface, suitable for exposed parts
Surface condition C is obtained by skin passing. The controlled surface for the exposed side enables application of a uniform paint finish. The reverse surface has, at least, the characteristics of surface quality B.
Surface finish
Galvanised (GI) grades with surface condition MC are available with different levels of surface finish. For exposed body panels with stringent paint appearance requirements we offer ‘regular’ surface finish. For panels with the highest paint appearance requirements we recommend the premium surface finish Serica FLO®.
Surface roughness
Metallic coated steel for automotive applications can be supplied in various grades of roughness to comply with individual customer norms. If no roughness is specified, roughness will be as shown in the table below
| Roughness Ra (µm) | |
|---|---|
| cut off 0.8mm | cut off 2.5mm |
| 0.6 - 1.9 | 0.7 - 2.2 |
Surface treatments
The surface treatments available are oiling and T-treatment.
Oiling (O)
The material surface can be oiled with preservative oil. Other types of oil - for increasing strength or reducing weight – are available to help achieve your optimum performance parameters. Please contact us for details.
Tata Steel offers the following range of oiling levels:
| Coating type | Oiling level |
|---|---|
| Pure zinc (GI) | 0.25 - 1.5 g/m2 |
| Zinc-iron(GA) | 0.5 - 1.5 g/m2 |
| MagiZinc Auto(ZM) | 0.25 - 1.5 g/m2 |
Other oiling levels are available on request.
T-treatment
Please contact us for further information.
Prime Lubrication Treatment (PLT)
Prime Lubrication Treatment facilitates the manufacturing of stamped components by minimising known issues in stamping and joining.
For further information please visit our Prime Lubrication Treatment (PLT) page.
EN-Automotive-Product-Metallic Coated-AHSS-CR DP800-Properties TSE
Properties
Mechanical properties
The available grades have the following mechanical properties. These are measured longitudinal to the rolling direction.
Property range is indicated according to VDA 239-100, but properties meet equivalent EN 10346 specifications also.
| Grade | CR DP800 | |
|---|---|---|
| Coating type | GI/GA | |
| Yield strength Rp0,2 | N/mm2 | 440 - 550 |
| Min. BH2 | N/mm2 | 30 |
| Tensile strength Rm | N/mm2 | 780 - 900 |
| Elongation | % | 14 |
| Min. r-value | - | |
| Min. n-value | - |
For galvannealed grades (GA) the minimum elongation before fracture is lowered by 2%.
Elongation after fracture A uses test piece length L0 = 80 mm.
Chemical composition
Tata Steel supplies the following cast analysis with maximum values in weight percentages:
| Grade | CR DP800 | |
|---|---|---|
| C | Max. | 0.18 |
| Mn | Max. | 2.50 |
| P | Max. | 0.050 |
| S | Max. | 0.010 |
| Si | Max. | 0.80 |
| Al | Max. | 1.00 |
| Cr+Mo | Max. | 1.40 |
All values are in weight%.
EN-Automotive-Product-Metallic Coated-AHSS-CR DP800-Dimensions TSE
Dimensional capability
Galvanised (GI) and Galvannealed (GA) products
Dimensions in mm.