New hot-dip galvanizing line from SMS group on stream at MMK
The Russian steelmaker PJSC Magnitogorsk Iron and Steel Works (MMK) has commissioned the new continuous hot-dip galvanizing line No. 3 in July 2017 according to schedule. The facility was completely supplied by SMS group (www.sms-group.com) and is designed to process 360,000 tons of galvanized cold strip per year. With this line, MMK has enhanced its production capacity of galvanized steel by almost 20 percent to reach an annual output of more than two million tons. The line serves for hot-dip galvanizing of cold-rolled, thin, low-carbon steel strips. To a large extent, the resulting products are employed in the construction and packaging industries. The facility was established in Magnitogorsk in the southern Ural Mountains on the site of rolling mill No. 11.
SMS supplied the complete line from one source, including mechanical equipment, process and furnace technologies as well as electrical and automation systems. The finished material has widths between 800 and 1,400 millimeters and thicknesses ranging from 0.25 to 1.0 millimeters. The maximum speed in the process section is 180 meters per minute, whereas in the entry and exit sections strip speed reaches a maximum of 250 meters per minute.
The first step in the line is to remove residual dirt particles from the strip surface in a cleaning section. A fully horizontal Drever furnace then heats the strip up to the required recrystallization temperature. In a subsequent gas cooling section, the strip is cooled to galvanizing temperature. The eco-friendly furnace is equipped with several facilities to recover energy, and the SMS-made downstream air knife system precisely sets the thickness of the zinc layer. Available for material post-treatment are a four-high skin-pass mill stand, a tension leveler and a spray passivation. Strip edge straightening and strip width adjustment are accomplished by an ASC twin-head side trimmer with integrated scrap chopper. This twin-head design of the shear permits the trimming knives to be changed in maintenance position while production is going on. Prior to coiling, additional protection of strip is provided by an electrostatic oiling machine.
SMS had already supplied to MMK a hot-dip galvanizing line and a universal annealing and hot-dip galvanizing line, which were both put on stream in 2012 with good results.