POSCO : 7CGL, the Automotive Steel Plant Exclusively for 'Giga Steel,' Has Been Completed

POSCO completed the construction of the world's first automotive steel plant built exclusively for 'Giga Steel.'

On April 26, POSCO held the completion ceremony for No. 7 CGL (Continuous Galvanizing Line), which can produce super-high-strength 'Giga Steel' with a tensile strength of 1.5 Giga, at the Gwangyang Steel Mill. More than 250 people, including POSCO CEO Ohjoon Kwon, Nak-yeon Lee, governor of Jeollanam-do, Hyun-bok Jeong, mayor of Gwangyang, and employees of customers and equipment suppliers, attended the ceremony. POSCO invested a total of KRW 255.4 billion, and the annual production capacity is 500,000 tons.

CEO Kwon remarked, 'POSCO opened up a new horizon in automotive steel by completing the construction of 7CGL that will specialize in the production of Giga Steel with a tensile strength of 1.5 Giga. POSCO will endeavor to create values together with customers by smartizing all our core equipment to solidify our global technology leadership, and providing differentiated products and customized solutions.'

Giga Steel, developed by POSCO, is super-high-strength steel that can withstand more than 100 kg of load per 1 ㎟. As the tensile strength, measured by pulling the steel plate from both ends until it is torn, is greater than 1 GPa, it was dubbed ''Giga Steel.' Even if you put 1500 1-ton semi-mid-sized cars on the palm-sized, i.e. 10 cm X 15 cm, Giga Steel, it can withstand the load. Accordingly, if POSCO Giga Steel is used, it will be possible to make a light but strong vehicle since it is over three times stronger than aluminum and has excellent formability.

In particular, 7CGL is attracting attention as the world's first plant that can produce both 1.5 Giga GA and GI steel for automobiles. GA (hot-dip galvannealed) steel is preferred by Asian automakers, e.g. Korean and Japanese automakers, because it has excellent coatability and weldability as the coating layer is made of iron and zinc alloy, and GI (hot-dip galvanized) steel is preferred by European automakers because it has excellent corrosion resistance as the pure galvanized layer wraps the entire steel sheet.

Previously, only 1.2-Giga GA and GI steel could be produced due to the surface and quality problems that occurred in the process of rapid cooling before and after plating. POSCO independently developed the 'high hydrogen rapid cooling technology' for making a high-strength structure in the steel plate before plating, and the 'rapid cooling system' that makes the plated surface look beautiful after plating through rapid cooling, and solved these problems.

In addition, POSCO leveraged its equipment technology and operating know-how it accumulated over the years to develop and manufacture core equipment, and design and construct the plant by its own efforts, thus reducing investment costs and securing cost competitiveness.

POSCO is planning to operate 7CGL as a plant producing high-end automotive steel in parallel with existing 5CGL, and provide customized solutions for customers demanding higher performance.

Meanwhile, as the construction of 7CGL is now completed, POSCO is operating 7 CGLs in Gwangyang alone, and 2 CGLs in Mexico and 5 CGLs in Thailand, India and China. It plans to further solidify its status as a global automotive steel maker based on 12 CGLs capable of producing 10 million tons after 2018.