Although the hot strip mil1 operation is small relative to the magnitude of the total steel manufacturing process, its smooth and efficient operation is an important. Rolling is the process of reducing the thickness or changing the cross section of a long workpiece by compressive forces applied through a set of rolls, as shown in figure 51. Pdf in hot rolling mills, premature failure of rolls is a major concern as it adversely affects the mill operation as well as production. Highest performing hot strip mills primetals technologies. The hot rolling process california steel industries, inc. A machine used for rolling metal is called rolling mill. An improved method for the hot strip mill production. The hot strip mill process hsmp is a highspeed, transient metal machining molding process. The hot strip geometry and microstructure also affects the final sheet geometry and properties, also after final cold rolling, so special attention must be paid to the hot mill process configuration and parameters. The process layout of some of the mills allows production of more than 5 million. Thermomechanical model for rolling and cooling of hot rolled. Hot rolling mills usually comprise the following process steps.
Hot working process for large rings and cold working process for smaller rings. Microstructure engineering for hot strip mills department. Hotrolling and coldrolling should not be mistaken for different grades of steel. A typical rolling mill consists of a pair of rolls driven by an. Steels of different grades can be produced as hotrolled or coldrolled.
Stresses from hertzian pressure in 4high cold mill back up rolls were measured years ago, the results were never published, but of high interest also, maybe later. Concretely, we focus on one critical process for manufacturing stainless steel sheets, the multipass hot rolling, a mill process which involves rolling the steel at a high temperature, enabling an easy shaped of it. We propose in this research a method to generate very good schedules. The strip mill was a major innovation in steelmaking, with the first being erected at ashland, kentucky in 1923. The goal is to extend the model of the hot strip mill at us steels gary works developed by a 2014 senior design group to estimate the temperature through the. Advanced automation system for dragon steels new hot strip mill. Compact strip production csp, or in conventional hot strip mills, has increased the requirements for precise massflow and thickness control. The thick steel slab passes through several rolling mill stands that are driven by powerful motors.
The hot strip mill represents the most productive solution for flat rolled products. Simulations of the hot rolling of u10mo coupons encapsulated in lowcarbon steel have been conducted following two different schedules. Thyssenkrupp steel europe spent a quarter of a million euros on renovating its hotstrip rolling mill in duisburg. This model runs in an offline mode, thereby saving many tons of wasted product that might be scrapped in trying to identify the proper mill setup. It provides the highest level of productivity together with a large product mix and outstanding quality. Advanced automation system for dragon steels new hot strip mill dragon steel corporation, a subsidiary of china steel corporation, commissioned a new hot strip mill at their greenfield steel facility in taichung, taiwan. Overview of the steelmaking process pellets sinter limestone coke iron ore coal scrap blast furnace ironmaking converter steelmaking ladle refining blast furnace steelmaking coalnatural gas plate hot rolled bars rods tube rounds rails slab billet bloom hot rolled and coldrolled strip coils structural shapes.
Hot rolling mill hgc thickness control improvement 98 another way to determine the thermal expansion of the work roll is the modelling of the heat transfer between the work rolls and the strip. In special applications, the drumtype shear also serves to divide transfer bars and finished plates. Pdf failure analysis of work rolls of a thin hot strip mill. The control of the temperature and the cooling patterns of a hot strip mill, in which hot rolled steel is cooled with water directly after the finishing mill and before the material is coiled, is. Thorough account of the hot rolling process and facilities as well as followup treatments given to hot rolled products. Analysis of a continuous heating process hot slab charging effects of skid system on heating 15. In the working process of the coiler, from the strip head. Based on the experience gained from more than 60 drumtype shears built so far.
The production of hot strip is a key element of steel production. The hot rolling process the primary function of the hot strip mill is to reheat semifinished steel slabs of steel nearly to their melting point, then roll them thinner and longer through 12 successive rolling mill stands driven by motors totaling 77,000 hp, and finally coiling up the lengthened steel sheet for transport to the next process. Data analysis of the hot rolling process in a stainless steel. Number ten of the manufacturing engineering and material processing series. Blazevic in this fourth volume of hot strip mill operations, the primary objectives are to separate localized shape distortions, such as buildup, from general shape problems, and to explain how buildup goes through the hot strip and cold strip mills. Youll appreciate xroll hot strip mills from sms group as allround plants for highquality hot strip. This depends on the roll speed, strip thickness, the properties of the strip, roll gap, contact time and cooling parameters. Yearly productivity of hot strip mills can vary from 2 to 6 mtpy, depending on the configuration that is selected.
Report on best available techniques bat in the german ferrous metals processing industry final draft deutschfranzosisches institut fur umweltforschung dfiu frenchgerman institute for environmental research university of karlsruhe th o. Mathematical modelling of roll wear in a tandem mill hot strip rolling process. In order to search for suitable technological schedule of hot strip mill, there is proposed an economomathematical model, in which production cost is a function of. Cstc of high strength steel for rot process in hot strip. Hot rolling mill hydraulic gap control hgc thickness. In most research on the hot strip mill production scheduling problem hsmpsp arising in the steel industry, it is accepted that a schedule with lower penalty caused by jumps of width, hardness, and gauge will result in lower roller wear, so it is regarded as a better schedule. Thin strip rolling was performed as a representative process under the rolling conditions of caser. As an initial step to meet these demands, primetals technologies has developed a new control concept for rolling ultrathin hot rolled strip in the finishing mill of an esp line.
The rolled sheets then pass through coilers, thereafter these coils move on to the next process in the plant. This provided a continuous process, cutting out the need to pass the plates over the rolls and to double them, as in a pack mill. Development of camber and steering control system in hot. The dimensional quality specification,4 consisting of thickness, width, flatness, and. Frequently asked questions about hot strip mill work roll. Secondary scale on hot strip and the impact on wear is another issue. The large wheel for stand r3 in the hot strip mill of arcelormittal, dunkirk, with a diameter of nearly 4,500 milli meters, a width of 1,300.
Report on best available techniques bat in the german. Hot strip mills have evolved in various steps from original tinplate and sheet rolling mills. Hot strip mill highest performance for new and existing steel mills the demand for hot rolled strip is growing in multiple ways. Camber and offcenter in hot strip rolling process cause various problems including clogging, defects on the strip, and telescope phenomenon in a coil. The differences between hot and cold rolled steel national. Hotrolling refers to a mill process in which you roll the steel at a temperature above its recrystallization temperature. The development of semicontinuous and continuous multistand mills followed, producing smalldiameter and eventually largediameter steel coil products. Pdf designing of hot strip rolling mill control system. They are designed to produce flat steel from thin strip with a minimum final gauge of 1. Hot strip mills have evolved in various steps from original tinplate and sheet rolling. Frequently asked questions about hot strip mill work roll surface wear, oxidation, firecracks, sticking and fiction this was originally presented at the wmsp, new orleans, 2004. The hot strip mill model hsmm is an invaluable tool to cost effectively assist in determining the optimum processing conditions to achieve the desired product properties. Ugi engineering works private limited is one of the most prestigious manufacturer, exporter, supplier, and consultant of high grade hot rolling mill. Heat transfer during the rolling process workpiece temperature change in hot strip mill temperature loss due to radiation temperature loss due to convection temperature loss due to water cooling temperature loss due to conduction to work rolls.
The emaintenance related to this rolling process is part of the challenging and innovative project simodim. Mar 31, 2015 thyssenkrupp steel europe spent a quarter of a million euros on renovating its hot strip rolling mill in duisburg. Pdf mathematical modelling of roll wear in a tandem mill. Manufacturing process steel making steel is normally manufactured in a basic oxygen furnace but could also be manufactured in electrical. When the tension control switch to the speed control, to cancel the additional speed. Model predictions of the rollseparation force and rollpack thicknesses at different stages of the rolling process were compared with experimental measurements. Bolong machinerydeformed barrebar hot rolling mill production line kirdemir turkey duration. Although other steels can also be purchased from arcelormittal south africa, availability is subject to enquiry. Rolling technology for thin steel strip in hot strip mill train1. The complete technology book on hot rolling of steel. To remain competitive, new and existing mills must meet this challenge in the best possible way.
Sms siemag hot strip mills 10 hot strip mill hot strip mill shanghai meishan, china the hot strip mill of chinese steelmaker baosteel group shanghai meishan corporation ltd. The primary purpose of a hot strip mill is to reheat thick steel slabs into thin sheets with varying thickness. Jun 30, 2017 bolong machinerydeformed barrebar hot rolling mill production line kirdemir turkey duration. Failure analysis of work rolls of a thin hot strip. Sms demag hot strip mills 10 the drumtype shear installed between the roughing and finishing mills of a hot strip mill crops the transfer bar at its head and tail. To reduce camber and prevent offcenter, we propose the integrated camber and steering control system based on adjusting roll gap level by previously designed mathematical model. The new mill is capable to produce about 3 million tyear of a broad variety of high quality steel strip. Karl heinrich schroeder with british rollmakers china ltd. The cold rolling process is carried out at low recrystallization temperature and it produces relevant small and thin pieces and temperature is low, therefore deformation becomes relatively difficult than the hot rolling process.
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