Driving the future: lighter, stronger, cleaner
The automotive world is moving quickly with urbanization and regulations pushing carmakers to develop safer, cleaner and affordable cars. POSCO, a leading steel producer from South Korea, secured its partnership with Fives by entrusting the group with a breakthrough project for its GIGA steel for the automobile industry.
POSCO contracted Fives for its reversible cold rolling mill DMS 20Hi EcoMill to process GIGA steel - Ultra Advance High Strength Steel (U-AHSS) and TWIP - for automotive applications.
For steelmakers and equipment providers, it is challenging to produce the highest tensile strength steel with 2,000 MPa to behave properly in crash behaviour and have better formability. Tensile strength refers to the maximum amount of stress a material can withstand while being stretched or pulled without breaking, and is measured in MPa, as a force per unit area - the unit being a pascal (Pa) / megapascal (MPa).
Since 2016, POSCO has been developing its GIGA steel for the automotive application due to its unparalleled properties. This steel is stronger than aluminium; and therefore, meets the most stringent safety standards. It has high formability to produce complex auto parts without any special processing. It leads the industry with the lightest weight which reduces emissions. Lighter vehicle body weight and significant reduction of CO2 emissions have been major drivers for carmakers.
The cold rolling mills are essential to reduce strip thickness while guaranteeing strip surface quality. With more than 100 references worldwide over last 60 years, DMS 20Hi cold rolling mills from Fives are proven for applications in stainless and silicon steels. In view of the fact that the mechanical properties of the UHSS or GIGA steel are similar to the ones of stainless steel, DMS 20Hi EcoMill was a silver bullet for GIGA steel processing. The robust monobloc housing and a fully controlled manufacturing process guarantee fabrication of the strongest cold rolling mill ever. It will have 180,000 tons production capacity, and will process ultra-high strength steel from 0.5 mm to 2.5 mm thickness on the strip width from 800 mm to 1,650 mm.
In addition, DMS 20Hi EcoMill combines several advances:
• Enhanced productivity thanks to the advanced strip wiping and strip cooling technologies
• Push-push 1st intermediate roll shifting system to reduce the risk of broken parts
• Improved strip surface quality due to the advanced strip cooling and flatness control system
• Quick and safe maintenance with minimal downtime due to easy access
Fives has already supplied a record number of references to POSCO worldwide: DMS 20Hi cold rolling mills for stainless steel to POSCO’s facilities in China, Vietnam and Turkey, as well as vertical annealing furnaces for continuous galvanizing lines at its Gwangyang Steelworks.