Evaluating the Suitability of Partial Recrystallization as a Strengthening Method for Thin-Gauge, High-Strength Non-Orientated Electrical Steel

The increasing need for electric/hybrid electric vehicles to compete with fossil fuel-powered cars has led to new requirements and designs of the electric motor. Non-grain oriented steel (NOES) is primarily used within the electric motor to form both stator and rotor sections (dependent on design) and has traditionally been developed to possess excellent isotropic magnetic properties with little or no consideration for strength. The drive toward more powerful or efficient electric motors has resulted in higher rotational speeds and increasing associated requirements for high-strength NOES. This paper looks at utilizing the well-known theory of partial recrystallization as a strengthening mechanism to determine if the strengthening effects and associated magnetic properties are acceptable for use within the rotor section. It was found that partial recrystallization can be utilized to tailor the microstructure of NOES to create higher strength NOES that withstands operating conditions and compares favorably to commercially available high-strength NOES grades, making it a viable option.