Driven by the dual forces of energy transition and smart manufacturing, electrical steel is undergoing profound transformation. As the core material for motor cores, the development direction of non-oriented electrical steel directly affects the energy efficiency and green progress of the manufacturing industry. This article provides an analysis from three dimensions: industry demand, evolution trends, and manufacturing technology.

1. The Electrical Steel Family: Different Roles of Grain-Oriented and Non-Oriented Steels

Electrical steel is mainly divided into two types: grain-oriented and non-oriented.

• Grain-oriented electrical steel (containing 2.9%–3.5% silicon) is processed to form a Goss texture, where grains are neatly aligned in a single direction, offering extremely high magnetic permeability in that direction. It is mainly used for transformer cores and is also called cold-rolled transformer steel.

• Non-oriented electrical steel is suitable for rotating magnetic fields and is widely used in various motors, making it a key material for improving motor efficiency.

2. Three Major Evolution Directions of Non-Oriented Electrical Steel

As manufacturing moves toward higher efficiency, intelligence, and green development, the demand for non-oriented electrical steel in China is showing three major trends:

1) Efficiency moving toward “ultra-high” levels

With the rollout of YE4 series ultra-efficient motors and IE5 ultra-premium efficiency projects, motor efficiency standards keep rising. This drives higher requirements for electrical steel's key properties: low core loss and high magnetic flux density.

2) Size moving toward lighter and more compact designs

In applications such as compressors and high-power ultra-high-speed motors, products with “small size, high power” are emerging. This drives silicon steel toward thinner gauges, higher strength, and lower loss.

3) Materials moving toward new solutions

The industry is collaborating with universities to explore new processes. One interesting example is using silicon steel scrap (e.g., edge trimmings, small chips) to produce motor cores via powder metallurgy. This new type of core can achieve core loss below 2.1 W/kg and magnetic flux density exceeding 1.7 T. It is expected that demand for high-grade silicon steel such as 50WW250, 50WW270, and 50WW310 will continue to grow.

3. Manufacturing Insights: The Core Technology of Grain Orientation Control

The manufacturing process of grain-oriented electrical steel reveals the key to silicon steel materials science — grain orientation control. The key to producing Goss-textured grain-oriented silicon steel lies in achieving “secondary recrystallization”:

• Adding inhibitors: Grain growth inhibitors such as MnS and AlN prevent grains from growing randomly during heating, ensuring that only grains with the desired orientation grow preferentially in subsequent steps.

• Precise heat treatment: The oriented nuclei required for secondary recrystallization are cultivated through accurate cold rolling and annealing processes, while maintaining a single-phase state in the material to avoid phase transformation disrupting the aligned grain structure.

Two typical process routes are used in production:

• Single-stage cold rolling with high reduction: using AlN as the main inhibitor.

• Two-stage cold rolling: using MnS as the main inhibitor.

It is worth noting that after normalizing and pickling, the hot-rolled coil should be cold-rolled as soon as possible. If left too long, carbon and nitrogen in the steel will precipitate, forming coarse second-phase particles that weaken the pinning effect and ultimately lead to degraded magnetic properties. Every step in the process must be precisely controlled, as it directly affects the quality of the final product.

Committed to Innovation, Driving the Future

At Shanghai Ruichao Industrial Co., Ltd, we are dedicated to advancing the science and application of electrical steel. By combining deep material expertise with advanced manufacturing capabilities, we deliver solutions that meet the evolving needs of the motor, generator, and transformer industries—today and into the future.

Welcome to partner with us as we power the next generation of energy-efficient technologies.