Bainite
Sophisticated bending
Our bainitic hardened and tempered PT-strip (pre-tempered) has an ideal combination of pre-adjusted component strength, good formability and good bendability. Thanks to this union of opposites it offers optimal spring properties, even for dynamic, highly-stressed parts. It is used, for example, in connecting, fastening and spring clips in mounting applications.
We also offer a special form of our bainitically hardened and tempered steel strip for cutting, stamping, and creasing lines. Thanks to a special annealing process, this makes it possible to combine a hard, durable material core with a soft, flexible surface.
Waelzholz owns special, high-performance machinery for bainitic hardening and tempering and is specialized in the production of PT-strip. This is how we guarantee absolutely homogeneous processing and forming properties as well as constant mechanical-technological characteristic values. Our customers benefit from the high- reproducibility of their components, as this translates to process stability. The greatest advantage of using PT-strip is the absence of time-consuming and expensive piece hardening. Stamped, bent and formed parts can be manufactured in one single step without any deforming or heat cracks. The result is optimal processing efficiency.
Application examples for Bainite
Further applications
Good Formability despite high strengths
Specifically, the good formability and bendability facilitate a wide range of demanding forming operations such as contours of stamped holes with a collar or dome-shaped drawing, notches and beading.
The differences between longitudinal bending and transverse bending are also minimal thanks to the homogeneous and fine-grained microstructure of the material. Because of this characteristic, our customers profit from maximum reproducibility of their parts and extremely high process reliability.
Sample application
PT 120 with a thickness of 1.7 mm (0.067") and a tensile strength of Rm = 1150 MPa (167 ksi)
1 Bending radius longitudinal to rolling direction
2 Collaring hole by drawing
3 Bending radius transversal to rolling direction
4 Notch
You will find the possible bending radii according to material thickness in the following table.
Grade and raw material overview / delivery types
Unit system
| PT90 | PT100 | PT120 | PT140 | ||
| Grade acc. to DIN EN 10132-3 and DIN EN 10132-41) |
e.g. 36Mn5 | e.g. C45E | e.g. C60S | e.g. C75S | |
| Tensile strength in MPa | 800 - 1000 | 900 - 1100 | 1100 - 1300 | 1300 - 1500 | |
| Yield/tensile ratio in % | ca. 80 - 85 | ca. 80 - 85 | ca. 80 - 85 | ca. 80 - 85 | |
| A802) in % | min. 16 | min. 14 | min. 9 | min. 5 | |
| Maximum longitudinal bending angle (bending radius = material thickness) in degrees |
> 110 | > 100 | > 90 | > 50 | |
| Maximum transversal bending angle (bending radius = material thickness) in degrees |
> 120 | > 110 | > 100 | > 60 | |
| Thickness in mm dimension tolerance acc. to DIN EN 10140 |
0.2 - 3.0 | 0.2 - 3.0 | 0.2 - 3.0 | 0.2 - 3.0 | |
| Width in mm dimension tolerance acc. to DIN EN 10140 |
5 - 450 | 5 - 450 | 5 - 450 | 5 - 450 | |
| Surface decarburization max. 2 % of thickness |
bright/ grey-blue finish | bright/ grey-blue finish | bright/ grey-blue finish | bright/ grey-blue finish | |
| Delivery condition | skin passed (+LC) or stretch-bended | ||||
| 1) Orders are placed acc. to material properties, the steel grades listed are only an example | |||||
| 2) Elongation value applies to the lowest tensile strength range | |||||
For more information on the PT-strip products, please refer to data sheets provided.