Technical Information - cold-rolled Spring Steel 301

Basic Information and Applications 301

Due to the alloy with 17% chromium and 7% nickel, this material has good corrosion resistance. With this material, high strength is achieved by cold rolling. Compared to material 1.4301, a significantly higher tensile strength up to over 2000 N / mm² can be achieved. The material 301 is therefore very well suited for rustproof precision training tapes and shims as well as for rustproof springs and parts with higher strength.

Further application examples include welded endless belts, conveyor belts and covers in machine tools. The material is approved as a spring material in the DIN EN 10 151 standard.

If there are high requirements for hardness and wear resistance, grades 1.4031Mo should be used (up to 2.00 mm thick) or 1.4034 (from 1.0 to 3.0 mm thick) can be used, If there are high requirements for corrosion resistance, use the materials 1.4404 or 1.4529
in hard-rolled condition. At high temperatures up to approx. 650°Celsius the material 2.4668 (Alloy 718) should be used precipitation hardened state can be used.

Delivery condition

Structure: cold rolled (austenitic with proportions of forming martensite), not hardenable

Surface: 2H, roughness Ra usually 0.10-0.3 μm (imprint of the work roll)

Tensile Strenght: 1100 to over 2000 N/mm²

The tensile strength can be increased by tempering the steel at 330-370 ° C (about 4 hours) by about 100-300 N / mm² depending on the original strength of the material. 

Tolerances

Thickness tolerance: DIN EN 9445 table 1 or T3 (for strength class 15-1700 N / mm²)

Width tolerance: according to DIN EN 9445

Straightness: normal

Flatness: Wave height max. 1.0 mm

mechanical Details

Elongation limit Rp0,2: depending on the tensile strength

Strain A80: depending on the tensile strength

With good edge processing after cutting (e.g. by surface grinding) the following values can be achieved:

Alternating bending stress (mean stress = 0): 550 MPa (50% of the test pattern survives 2 million cycles in normal surroundings), with a bend perpendicular to the rolling direction.

Tensile threshold stress (minimum stress = 0): 420 MPa (50% of the test samples overlook 2 million cycles in normal surroundings), with a bend perpendicular to the rolling direction.

Since the fatigue strength depends on various factors such as the ambient conditions and the edge properties, no values can be guaranteed. In the case of heavy loads or bending that are not perpendicular to the rolling direction, hardened steels such as 1.4301Mo are required.

Depending on the load, the highest application temperature is between 120 and 250 ° C (cf. DIN 17224 - spring band made of stainless steel). Please note that the values for the modulus of elasticity decrease with increasing temperature.

Alloy Designations

Material - Composition*

* for the exact composition can be documented in the form of a test certificate 2.2 or 3.1 (according to DIN 10 204) for each batch.

Physical Information

Processing information 301

Punching: The cutting gap should correspond to approximately 10% of the strip thickness. The corner radii should be at least 0.25 and the punch diameter min. be twice the tape thickness. For stamped parts, post-treatment by slide grinding is necessary to achieve good fatigue strength.

Laser cutting: This material 301 can be laser cut very well.

Etching: The material is very easy to etch.

Bending: Since the high strength of the material is achieved through cold forming during rolling, the rolling direction has a major influence on bending.

The recommended minimum bending radius also depends on the tensile strength.

Bending transversely (perpendicular) to the rolling direction:

 t = thickness

Bending lengthways (parallel) to the rolling direction::

 t = thickness

Recommended strength class for bent parts: 11-1300 N / mm²

Surface grinding: In the hard-rolled state, material 301 is only weakly magnetizable and cannot be clamped on magnetic chucks of grinding machines.

In the soft-annealed condition, it has an austenitic structure and is therefore almost unmagnetizable. Hard rolling causes the formation of forming martensite and thus an increase in magnetizability. Since this is influenced by various factors such as the degree of forming, the material temperature during rolling and also the alloy composition, no special values ​​can be given. With a degree of deformation of 50%, the magnetic permeability is a maximum of 10.0 to 18.0 and with a degree of deformation of 70% a maximum of 15.0 to 24.0 (at 200H).

For springs in a magnetic environment, we recommend stainless spring strip steel 1.4529, which is almost non-magnetizable even when hard-rolled due to its high austenite stability (in stock in thicknesses of 0.05-0.50mm).

Welding: The 301 is very easy to weld like other austenitic stainless steels. However, the heat input at the weld seam can lead to a structural change that reduces the strength.

Due to the higher carbon content of approx. 0.10%, local corrosion can also occur on the weld seam.

Chemical Resistance 301

Assignment in group 4 of the stainless steel table for the chemical resistance of stainless steels. Nirosta is a registered trademark of ThyssenKrupp AG.

This material is therefore less corrosion-resistant than material 1.4404 (group 5), but better than materials 1.4034 and 1.4031Mo, which are both in group 1.

Please check there or by tests to determine whether material 301 is sufficiently resistant to your application. Material 1.4404 or 1.4529 should be used for applications in corrosive environments.

Important NOTE

The technical information listed above or the information provided on the nature or use of the materials serve for description and are not a guarantee of properties. The information with which we want to advise you corresponds to our experience and that of our upstream suppliers. We cannot guarantee the results of processing and application. (03/2024)