powercore® Traction for high frequencies and e-mobility

For improved efficiency and power density

Our powercore^® Traction electrical steel is a highly pure, magnetically soft iron-silicon alloy that is used to guide and concentrate the magnetic flow present in the motor.

The powercore^® Traction non oriented grades meet the demands of high-performing and efficient drive systems. They are very thin, have homogenous mechanical properties, low remagnetization losses, and high polarization.

Two new electrical steel grades from the powercore^® Traction product family are in the final development phase. Shortly, they will join thyssenkrupp Steel's portfolio of materials for particularly energy-efficient electric motors. At just 0.25 mm, the particularly thin electrical steel strips of type NO25 have excellent magnetic properties, high mechanical strength, and are characterized in particular by very low remagnetization core losses – important for use in high-performance traction motors of electric vehicles.

The two new developments are characterized by very low remagnetization core losses of 12.5 watts per kilogram and 13 watts per kilogram, respectively. This means we've been able to improve them by up to 11% compared to current reference grades. Of course, the other magnetic parameters of the new grades, for example polarization, also achieve peak values. The series ramp-up of the new NO25 grades in the new plants is planned; sampling and homologation inquiries can be made immediately.

Gets electric mobility rolling: powercore^® Traction electrical steel

The electric motor is the heart of the electric vehicle, and electrical steel is indispensable for the electric motor. powercore^® Traction electrical steel strip has been specially developed and optimized for the high demands of electric mobility. Rüdiger Schorn, Product Manager for Electrical Steel at thyssenkrupp Steel Europe, explains what the high-tech material can do, how different motor types and drive systems affect the demands placed on it, and what the consequences are.

1. What is powercore^® Traction?

Our powercore^® Traction electrical steel is the logical further development of our non-oriented (NO) electrical steel for the high demands of electric mobility: High efficiency for long ranges, high torque for maximum driving dynamics, and all this under high cost pressure.

2. How does electrical steel strip drive the electric motor?

Our powercore^® Traction grades are used to build what are referred to as rotors and stators. In the process, our grades amplify and direct the magnetic flux in the coils. Typically, a rotating magnetic field is generated on the outside of the stator, which is followed by the rotor on the inside. However, there are very different motor types and drive philosophies in current electric vehicles. Asynchronous machines and synchronous machines, permanently excited – i.e. with magnets – or separately excited, with single-speed or multiple-speed gearboxes. Each combination results in a different requirement profile for the electrical steel strip. Therefore, powercore^® Traction also stands for a product family with various different grades. We operate our own motor test bench in our Application Technology department, where we test our powercore^® Traction grades in the various motor types. This enables us to provide our customers with the best possible advice on selecting the right grade depending on the customer's specific requirements.

3. What properties must the electrical steel strips have for this?

As already mentioned, this depends very much on the respective motor and drive concepts. The trick is to always ideally match the 3 core requirements of low power dissipation, high polarization and mechanical strength to each respective application of our customers, in addition to many other requirements. A basic requirement that always applies is to achieve properties that are as homogeneous as possible over the strip length and width. This applies to the magnetic properties as well as to the mechanical properties and geometric tolerances, which are highly relevant for the die cutting and packaging processes.

Electrical steel for e-mobility and high frequencies
DIN EN 10303

Steel grade	Reference grade DIN EN 10303	Thickness	Density	Max. Core loss at	Min. Polarization at			Yield strength
		[mm]	[kg/dm³]	400 Hz 1.0 T [W/kg]	2,500 A/m [T]	5,000 A/m [T]	10,000 A/m [T]	R_p0.2 [MPa] min.
powercore^® Traction 020-130Y320	NO20-13	0.20	7.60	13	1.48	1.59	1.69	320
powercore^® Traction 020-130Y350	NO20-13	0.20	7.60	13	1.48	1.59	1.69	350
powercore^® Traction 020-150Y320	NO20-15	0.20	7.60	15	1.48	1.59	1.69	320
powercore^® Traction 025-140Y400	NO25-14	0.25	7.60	14	1.52	1.61	1.71	400
powercore^® Traction 027-140Y420	NO27-15	0.27	7.60	14	1.51	1.61	1.73	420
powercore^® Traction 027-150Y370¹	NO27-15	0.27	7.60	15	1.52	1.61	1.73	370
powercore^® Traction 027-150Y420¹	NO27-15	0.27	7.60	15	1.52	1.61	1.73	420
powercore^® Traction 027-180Y370¹	NO27-18	0.27	7.60	18	1.52	1.61	1.73	370
powercore^® Traction 030-160Y420¹	NO30-16	0.30	7.60	15	1.52	1.61	1.73	420
powercore^® Traction 030-150Y420¹	NO30-16	0.30	7.60	16	1.52	1.61	1.73	420
powercore^® Traction 032-190Y330¹	NO35-19	0.32	7.65	19	1.52	1.62	1.74	330
powercore^® Traction 035-170Y420¹	NO35-19	0.35	7.60	17	1.52	1.61	1.73	420
powercore^® Traction 035-180Y400	NO35-19	0.35	7.60	18	1.52	1.61	1.73	400
powercore^® Traction 035-190Y390	NO35-22	0.35	7.60	19	1.52	1.61	1.73	390
powercore^® Traction 035-220Y300	NO35-22	0.35	7.65	22	1.55	1.64	1.76	300
powercore^® Traction 035-220Y330	NO35-22	0.35	7.65	22	1.52	1.62	1.74	330

1. Steel grades are characterized by very good processing properties with advantages in final applications.
R_p0.2: Yield strength to DIN EN ISO 6892-1 in rolling direction at room temperature.