1. Application examples
A small addition of about 0.40% chromium leads to higher wear resistance and better hardenability with large cross-sections in this carbon steel. With a Rockwell hardness of 47-51 HRC, this material is also suitable for smaller tools.

Available in sheets in the size 350x1000mm and 610x1220mm, in some thicknesses different siezes are possible (see chapter 5).

In the thickness range between 0.02 and 3.00 mm, the hardened spring steel W.-Nr. 1.1274 is available.

2. Material codes
German Norm: 1.2003 75Cr1
AISI: equivalent to 1075 + Chromium
ASTM: equivalent to G 10780 + Chromium
Engl. Norm: equivalent to 80 (Norm 5770 Part3)
French. Norm: XC75 + Chromium
Japanese Norm: -

3. Alloy Composition *
C: 0,70-0,80%
Si: 0,25-0,50%
Mn: 0,60-0,80%
P: max. 0,03%
S: max. 0,03%
Cr: 0,30-0,40%

* the exact composition of each batch can be documented by a material certificate 2.2 or 3.1 according to DIN EN 10 204.

4. Delivery condition
Condition: hardened and tempered
Surface: not polished, Ra 0,30 – 0,60 µm
Flatness: max. 0,20% of the strip width
Hardness: 48-50 HRC

Further mechanical data: see chapter 7 and 8.

5. Sizes
thicknesses: 0,60-5,03 mm
Standard sizes: 350x1000mm and 610x1220, in some special thicknesses differing
edges: cut (in the non-hardened condition)

6. Tolerances:
thickness tolerace: usually +/- 0,03mm
width tolerance: B2
straightness: normal

7. Further mechanical data
Yield strength Rp0,2 : ca. 90 % of the ultimate tensile strength
Elongation A80: no values available

The highest application temperature is around 200° Celsius, depending on the load. Please note that Young's modulus values drop as temperature increases.

For higher operation temperatures we suggest the stainless hardened steels like the alloys 1.4031Mo (up to 0.80 mm thickness) and 1.4034 (from 1.0 to approx. 10.0 mm thickness)

8. Physical properties (for alloy 1.1248 = C75S)
Density: 7,9 g/cm³
Thermal conductivity: 49 W/(m °C) at 20 °C
Spec. heat capacity: 460 J/(kg °C) mean value at 50 – 100 °C
Thermal expansion:
   10,5 x 10 -6 (between 30 - 100 °C)
   11,5 x 10 -6 (between 30 - 200 °C)
   12,5 x 10 -6 (between 30 - 300 °C)
Electric resistance: approx. 0,20 Ohm x mm²/m (for 1.1231= C67S hardened)

Modus of elasticity: 210 000 MPa at 20 °C
Relative permeability µr: maximum 400 (for 1.1231= C67S hardened)

The given values can be used as indication for the alloy 1.2003 (75Cr1).

9. Blanking
This material should not be blanked due to the high hardness and thickness. We suggest to produce pieces by laser cutting or water jet cutting.

10. Laser cutting
As the material melts at the edge during laser cutting, a higher hardness and therefore a lower toughness at the cutting zone is possible.
We suggest to produce critical pieces by water jet cutting.

11. Photo etching
Due to the thickness of more than 0,60 mm it is not economical to produce parts by photo etching.

12. Bending
As this material is supplied in the hardened and tempered condition, the rolling direction is not important regarding the bending.

Bending radius: minimum 10 times of the strip thickness.
Spring back angle:

As the spring back angle depends on several factors, bending tests are necessary. As guidance an angle of 10° at a strip thickness of 0.20 mm and an angle of 20° at a strip thickness of 0.60 mm can be expected.

13. Flat grinding
The alloy 1.2003 is magnetisable and can be fixed by magnetic clamping devices of flat grinding machines.

14. Welding
Due to the high content of carbon the alloy 1.2003 should not be welded.

15. Corrosion resistance
The alloy 1.2003 is not corrosion resistant. We supply this alloy with a light oil film. If used at normal conditions this alloy needs to be painted or galvanized.

Important
The specifications which are given in this technical information sheet about the condition and application of the alloys are only for reference and are no confirmation about certain performances and characteristics.
The information correspond to our own experiences and experiences of our suppliers. We can not guarantee for the results during processing and utilisation.