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Resolving complex shape distortions on 20-high mills rolling narrow, thin gauge strip having an asymmetric transverse thickness profile
By Mark E. Zipf, Cold Rolling Technologies, Inc., USA
Certain cold reduction operations involve the rolling of narrow, thin gauge strip having an asymmetric (wedged) transverse thickness profile, formed from wider, symmetric profiled material being slit along the longitudinal centerline. It’s not uncommon for this narrow, asymmetric strip to be rolled on mills having a substantially wider roll face. In these cases, the mill’s shape actuation control range is strongly compromised, limiting the ability to actively address and correct highly localized, complex shape distortions. This paper examines this difficult operating condition and a method to resolve the situation through measurement and analysis of the mill’s housing and roll cluster geometry, coupled with the selection roll cluster mechanical crown and tapers (mill set-up).
Confined Jet Dryer - a definitive answer to solution stain in cold rolling
By Luciano Vignolo, Daniele Borlini, Danieli Officine Meccaniche S.p.A., Italy
In cold rolling if solution stain is present on the strip surface the material has to be reprocessed or rejected and the part of coil with the defect is considered as scrap. At present no equipment is available on the market to completely solve this quality issue. Danieli Wean United, after an intensive activity of Danieli Research & Development, has realised an innovative equipment named Confined Jet Dryer (CJD) that in addition to the equipment used to seal the exit strip gap of a rolling stand is able to remove every droplet eventually present on the strip surface. This patent pending solution is part of a robust drying system designed by Danieli and can be added easily. Because of the small required space (less than 0,5 m), it can be applied also in existing rolling mills to apply this blow-off method for producing a spotless and clean rolled strip. This solution can be applied for all cold rolling processes for sheet thickness variable in the range 0.18÷0.30 mm, if water based emulsion is applied for roll lubrication and cooling.
Improved coating range and uniformity via X-JET air knife combined with strip stabilizer, for lower OPEX production
by Enrico Vettori, Gianluca Caporal, Danieli & C. Officine Meccaniche S.p.A., Italy.
The Danieli X-JET: Maximum wiping capability with minimum flow and pressure resulting in the optimum Operating Range. It is well known that for any jet wiping system there are substantial benefits to working as close as possible to the coated strip where the jet is still substantially laminar. It is possible to make the lightest possible coating for a given speed. Coating appearance is improved. Edge overcoating is minimized. Using minimum pressure and flow diminishes splashing and the need for skimming. At the same time, strip shape deviations and vibrations limit the ability to operate close to the strip. The unique character of the X-JET keeps the laminar region much farther away from the nozzle exit. This means that the X-JET can obtain the benefits associated with operating close to the strip while operating at a greater distance.
This improved Operating Margin allows the operator to minimize the effects of strip shape deviations and vibration. It is possible to minimize edge overcoating with all combinations of line speed and coating weight, improve coating uniformity, minimize operating costs for blower power and/or nitrogen usage and minimize splashing and skimming while maintaining superior high speed/light coating capability. The jet lips require less cleaning. The reduced skimming and lip cleaning improve operator performance and safety. Use of the Danieli electromagnetic strip stabilizer further enhances performance by providing a flatter, more stable strip. The improved strip shape and position allows the operation of the X-JET to be optimized resulting in even better coating uniformity and lightest possible minimum coating.
High-performance shears for blooming and billet mills
By V.A. Bykov, P.B. Sokolov, Y.D. Makarov, S.?. Mikulchik, “Uralmashplant” JSC (Ekaterinburg, Russia)
As compared to the existing analogs, the offered design of the upcut shears allows improving considerably the quality of rolled material cutting through the optimization of the bottom blade motion path, simplifying the manufacturing process and enhancing the operating conditions of the shears. The technical feasibility of cutting the strip into billets without any burrs was confirmed in practice. Also, a method of top and bottom blade installation was substantiated; this considerably reduces the deformation of billet ends. The shears with cutting force of 14 MN manufactured by Uralmashplant and implemented at the blooming mill of JSC EVRAZ ZSMK improved the quality of cutting, that is, their implementation led both to a decrease in deformation of cut billet ends and to a reduction of cutting power requirement by 20%.
High speed thermal imaging cameras from FLIR monitor raw steel quality for the automotive industry
By Our News Bureau
in today's industrialized world the demand for steel, particularly from the automotive industry, has became overwhelming.
Increased pickling line productivity, eliminated downtime the HRS way
By Our News Bureau
Steel plants are engaged in many heat treatment processes like forming, rolling, forging etc. These processes which occur at high temperatures leave a discoloured oxide layer or something similar to very heavy rust on surface of the steel, called ‘Scale’, which needs to be removed to separate oxides and iron contamination. ‘Pickling’ is a metal surface treatment used to remove scale or alike contaminations by dipping the rolled material into the solution of strong acids, also termed as ‘pickle liquor’.
E4.1L from igus – low weight, easy assembly and cable-friendly design
By Our News Bureau
Optimum use of installation space, light weight and high stability – these are just some of the benefits of the E4.1L energy chain from igus, which is now available in new heights and widths from stock. Compared to the E4.1, weight can be reduced by 30 percent, with this light version, meaning that the chain is well suited to highly dynamic applications. It was developed especially for unsupported applications; long gliding travels are also possible with the e-chain.
First hot coil on the continuous annealing line built by Fives at Guangxi Steel
By Our Correspondence
Fives and Guangxi Iron & Steel Group Co., part of WISCO grouphave successfully processed the first hot coil on a new continuous annealing line (CAL) on March 15, 2016 for the new 10 million ton plant in Fangchenggang, at the southern coastal region of China.
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