Production of sellable steel strips directly after the first coil
by Hans Diederichs
Shougang Jingtang (Shougang Jingtang United Iron & Steel), China, successfully commissioned the new hot-dip galvanizing line supplied by SMS group (www.sms-group.com). The new line is especially equipped to produce high-strength grades with tensile strengths of up to 1,350 MPa. The capacity is 360,000 tons per year of hot-dip galvanized steel strip, which will be used mainly in the automotive industry to produce structural parts and car body shells for lightweight cars. The first coil was produced on November 13, 2019. Direct after the start-up Shougang Jingtang was able to produce 1,000 tons of sellable galvanized material. A second campaign of 5,000 tons was produced in December 2019.
The new hot-dip galvanizing line is the sixth strip processing line SMS group installed for Shougang Jingtang on Caofeidian Island, a man-made island offshore the Chinese province of Hebei. Besides the good experience with SMS group the main reason to decide in favor of SMS group as supplier of the new line was SMS group’s vast experience in the field of high-strength steel strip. The exit section is designed to even process steel strips with a tensile strength of up to 1,500 MPa, since Shougang Jingtang plans to use the line also for developing new materials. Thus, especially the skin-pass mill, tension leveller and side trimming unit have been designed specifically for these requirements.
The hot-dip galvanizing line processes strips up to 1,580 millimeters wide and between 0.6 and 3.0 millimeters thick. Strip speed during the galvanizing process is maximum 160 meters per minute. The product range includes high-strength grades such as HSLA, DP and Q&P as well as soft steel grades. To satisfy particularly high demands on surface quality, a FOEN air knife precisely and homogeneously sets the thickness of the zinc layer. The air knife system is equipped with a contact-free edge mask, automatic gap width adjustment and HD cameras for continuous quality monitoring.
In addition to the engineering for the complete mechanical equipment and the manufacturing of high-quality key components, SMS group’s scope of supply also included equipment installation and commissioning. SMS group also supplied all electrical and automation systems. EMG Automation provided the strip guiding system including BREIMO strip width measurement and EMG SOLID® oil layer thickness measuring equipment.
Source and photo: SMS group