Posco Reaches 1 Million Tonne Capacity for Auto Steel at Gwangyang
Strategic Research Institute
Published on :
20 Sep, 2021, 5:46 am
Korea Herald reported that South Korean steel maker Posco has established a 1 million tonne production facility inside the Gwangyang steel mill in Gwangy in South Jeolla Province of South Korea for giga steel, an ultra high strength steel product used for cars, by investing KWR 500 billion (USD 425 million) since 2017. Posco’s Steel Business Chief Mr Kim Hak-dong said “Since its first production of steel in April 1987, Gwangyang Steelworks has grown into the world’s largest steel mill producing the best automotive steel products. I am confident that, from establishing the 1 million tonne production system, Posco will stand in a position of advantage in the global market as an eco-friendly auto parts supplier in the fast-growing new mobility market.”
Citing data from IHS Markit, Posco said the global giga level steel industry is expected to grow 13% annually. The global production volume of the high-strength steel was 6.7 million tonnes in 2020, and the market research firm viewed it would rise to 12.4 million tonnes in 2025.
More than ever, the industry is requiring that a vehicle goes longer distances with less fuel, which means the car must be lighter. Also, technological advances have enabled cars with more power, requiring them to be safer. Consumers also want a car that represents their personality, demanding vehicles with more sophisticated and elegant designs. While there are other conditions that need to be considered, it is paramount that cars meet the following three conditions in order to satisfy consumers: fuel efficiency, safety, and design. But these demands are becoming increasingly difficult to meet, and the only solution is to discover a technology that enables all of the above. For safety considerations, in the event of a collision, parts of the car also need to absorb the kinetic energy and protect the passengers inside.
POSCO GIGA STEEL is an advanced high-strength steel that can meet these various demands. 6 different types of POSCO GIGA STEEL products are being used in different parts of the car.
- Complex Phase (CP) steel is often used to make reinforced auto parts that require high crashworthiness ratings, such as sill side panels, bumper rails, and door impact bars. It plays an extremely important role in the car frame as it is highly resistant to dents or bumps. In the past, the side panels of race cars were purposely made to be thicker in order to prevent dents and protect the driver inside and this naturally led to the vehicle becoming considerably heavier. However, CP steel minimizes these disadvantages. In the event of an impact, cars made with CP steel retain its original shape considerably better than other car frames due to its high strength and also has an exceptional ability to absorb all of the energy while still exhibiting an impressive thinness. It is often incorporated into the sill side panels and door impact bars to allow for a more spacious design.
- Dual Phase (DP) steel can be easily welded and deformed and boasts a high level of total elongation (the rate at which the material is stretched without snapping). DP steel is commonly used in seat rails or other lower body reinforcements that run underneath the passenger seat. The tensile strength is at least 980MPa, but because it also exhibits impressive ductility, it can easily be used for random spare parts.
- Transformation Induced Plasticity (TRIP) steel first made its way into the auto industry about six years ago. As the auto industry is beginning to value lightweight cars more and more, TRIP steel has received more attention. It is mainly used in the inner parts of the car body. This part of the car needs to absorb shock and impact and also be flexible enough to be fitted around the complex inner structure of the car. With TRIP steel’s outstanding combination of strength and ductility, it is one of the most commonly used high-strength automotive steels in the auto industry today.
- Martensite steel (MART) is naturally high in strength which allows thinner sheets to be used with less weight. Because Martensite steel is naturally high in strength, thinner sheets produced from roll forming (a metal forming process in which steel is continuously shaped or formed until it reaches a desired cross-section) still retain the same level of performance as conventional parts. Thinner parts also have the added benefit of reducing the weight.
- Hot Press Forming (HPF) Steel is often used in the B-pillar of a car which requires intricately shaped parts as well as the A-pillar roof side rails which are prone to damage. Hot Press Forming (HPF) steel is a different class of steel made with a unique steel production process. Typically, as steel becomes higher in strength, it is more difficult to mold into the desired shape through conventional processes. However, through the HPF process, the steel is heated to 950? before press forming. At high deformation temperatures, steel sheets are very soft so that difficult shapes can be obtained easily. During forming, the heated steel sheet cools down rapidly in the die block, so that the resulting pressed parts have a very high strength level. Due to its combination of high strength and formability, HPF steel is often used in the B-pillar of a car which requires intricately shaped parts as well as the A-pillar roof side rails which are prone to damage.
- Post Heat Treatment (PHT) Steel boasts both ultrahigh strength and toughness. The chassis that supports the car frame needs to be extremely durable and resistant to impacts or shocks on the road as its main function is to improve the ride quality of the vehicle. In order to increase the durability and torsional resistance, the material needs to be quenched and tempered. Before going through the heat treatment portion of the process (quenching), the material can be easily molded into spare parts due to its reduced strength. After being molded, it is heated up to 950°C and then rapidly cooled by water. This is why PHT is called “post-heat treatment steel”. Due to its ultra-high strength, it also has lightweighting benefits and is typically used in a vehicle’s chassis, stabilizer bars in a suspension system, and torsion beams.