[Report] Ready to Produce Motor Steel Sheets for 5 Million Electric Vehicles... "Aiming for Global No.1"

Visiting POSCO Gwangyang Steelworks 3rd Hot Rolling, 4th Coating, and Electrical Steel Sheet Plants
Targeting the Eco-Friendly Vehicle Market
Producing Ultra-High-Strength Automotive Steel Sheets and Electric Vehicle Drive Motor Cores

On the 30th of last month, inside the No. 3 Hot Rolling Mill at POSCO Gwangyang Steelworks, an orange object passes through the rollers. It is a steel slab, a semi-finished product, heated to 1200 degrees Celsius. Even when viewed from the height of a five-story apartment building, the heat felt like being inside a sauna. As the slab moves about 500 meters, it is gradually thinned as it passes through various rollers. At the end of the line, it is rolled up into a shape resembling a roll of toilet paper. The surrounding temperature drops from that of a wet sauna to roughly the outdoor weather of Southeast Asia.

Products are being produced at the POSCO Gwangyang Steelworks 3rd Hot Rolling Mill.
[Photo by POSCO]

The hot-rolled coils produced here are used directly as industrial machinery or construction materials. They can also be further rolled at room temperature to become high-quality products with a smooth surface. One representative example is the hot-dip galvanized steel used for automobile bodies or chassis. Inside the steelworks, the No. 4 Coating Plant processes hot-rolled products through pretreatment to remove impurities, heat treatment to secure mechanical properties, galvanizing, and alloying, transforming them into lightweight yet strong automotive steel sheets.

Interior view of 7CGL at Gwangyang Steelworks 4th Coating Plant.
[Photo by POSCO]

Within the steelworks, construction is underway for a factory to produce electrical steel sheets used in electric vehicle (EV) drive motors. The electrical steel sheets produced here are used to make the iron cores of rotating machines such as EV drive motors. The motor cores (stator and rotor) exhibited by the company are used in electrified vehicles from leading domestic and international automakers. In April last year, POSCO invested 1 trillion KRW to build a factory with an annual production capacity of 300,000 tons. The first phase is scheduled for completion in October, and trial operations began earlier this month. The company plans to increase annual production of electrical steel sheets from 100,000 tons at the existing Pohang Steelworks to 400,000 tons combined with Gwangyang by October 2024. This amount is sufficient to produce motor cores for 5 million electric vehicles.

Gwangyang Steelworks Electrical Steel Sheet Plant Construction Site
[Photo by POSCO]

POSCO aims to target the eco-friendly vehicle market by expanding production of ultra-high-strength steel sheets and steel sheets for EV drive motors. The Gwangyang Steelworks, the world's largest steelworks by single scale, is leading the charge with ambitions to become the "world's number one steelworks for automotive steel sheets."

The company is already achieving strong results in the high-quality automotive steel sheet sector. Last year, the steelworks supplied approximately 8.2 million tons of automotive steel sheets. Considering that about 1 ton of steel sheet is used per vehicle and the global annual automobile production is around 80 million units, one out of every ten cars worldwide uses POSCO steel sheets.

Products are being produced at the 7CGL of the 4th Coating Plant at Gwangyang Steelworks. [Photo by POSCO]

The secret lies in simultaneously meeting the difficult-to-reconcile properties of being both lightweight and strong. Electric vehicles are 25% heavier than internal combustion engine vehicles due to battery weight. Automakers focus on lightweighting while also emphasizing the development of strong bodies that ensure passenger safety. POSCO's Giga Steel has a tensile strength of over 1 GPa (gigapascal), capable of withstanding weights exceeding 100 kg per square millimeter. It can be made as thin as 0.5 mm, making it lightweight.

Kim Changmook, Group Head of POSCO Automotive Materials Marketing, said, "We collaborate closely with customers from the material development stage," adding, "We will accelerate the development of next-generation steel grades to lead the eco-friendly vehicle era."

Exterior view of Gwangyang Steelworks Electrical Steel Sheet Plant [Photo by POSCO]

POSCO is not only satisfied with body steel sheets but is also focusing on interior materials for electric vehicles. It has begun full-scale production of non-oriented electrical steel sheets (NO) for drive motors. The non-oriented electrical steel sheets produced by POSCO are highly efficient and are called Hyper NO. Only a handful of steel companies worldwide produce such high-efficiency steel sheets, and POSCO is the sole producer in Korea.

Electric vehicle drive motor core produced with electrical steel sheet made by POSCO [Photo by POSCO]

Energy loss during the conversion of electrical energy to rotational energy is 30% lower compared to general electrical steel sheets. The iron loss (power loss occurring in the motor core's iron core) is also low at 3.5 W/kg, helping to extend the driving range of electric vehicles. This makes POSCO a key player in the automotive downstream industry, playing a decisive role in enhancing vehicle performance in line with the electrification trend of electric and hybrid vehicles, as well as ensuring the fundamental value of safety pursued by automobiles.

Ahn Hyungtae, Head of POSCO Hyper NO Task Force Team, said, "Hyper NO products are representative eco-friendly materials used to make iron cores for rotating machines such as motors and compressors," adding, "By improving motor efficiency, they minimize the cost of building new power plants that generate electricity, thus having a significant impact on the overall domestic manufacturing industry."

This content was produced with the assistance of AI translation services.