A broad range of solutions are offered for metallic coating of both hot-rolled and cold-rolled strip in continuous hot-dip or electrolytic coating lines. This value-added, high-quality material is extensively used in construction, in appliances, in automotive and in packaging applications as a well-proven and time-tested solution for corrosion protection.
Primetals Technologies designs and implements galvanizing lines for hot and cold rolled strip, combined galvanizing and color coating lines, and combined pickling and galvanizing lines. We have developed our own in-house technologies for ensuring the highest product quality in the hot-dip galvanizing process.
Primetals Technologies' metallic coating lines stand for reliable operation, high throughput rates and top product quality. The lines assure the highest degree of flexibility for changing strip steel grades, coating compositions, and strip dimensions. The lines guarantee production of first-class output material which meets the most stringent demands of the market such as automotive grades (e.g. Extra-Deep Drawing Quality, High Strength, Hot Formed or Martensitic Steels) and external surface quality as well as for household appliances and construction applications. All kinds of coatings can be applied including Pure Zinc, Galvannealed (ZnFe), Galfan (Zn95 Al), Zinc Aluminium (Al55Zn), Aluminium Silicon (AlSi) or pure aluminium (Al) offering the widest range of strip protection to customers' targeted markets.
Galvanizing of Cold-rolled Strip
- Strip welding by Mash Lap or Laser depending on final application
- Cleaning section
- In-line multi zone annealing furnace
- Zinc pot dross removal system
- Air knives working in closed loop control with zinc coating gauge
- Electromagnetic strip vibration damper and crossbow corrector
- Strip roughness and mechanical properties controlled with our skin-pass mill and tension leveller
- Roll coater installed in post treatment section
- Single head or turret-type side trimmer
- SIAS® – automated surface inspection system
- Coating applications for virtually all strip qualities, including extra-deep drawing grades with yield strengths down to 160 N/mm²
- Galvanized strip surfaces ideal for automotive exposed parts and home appliance applications
- Fully automated operation with in-line quality control
- Integrated environmental solutions that reduce energy, chemicals and process-water used
- Easy maintenance and operation due to ideal equipment design
Fig.1- Layout of continuous galvanizing line
Galvanizing of Hot-rolled Strip
Recent advances in hot-strip rolling now allow strip to be rolled to gauges of less than 1 mm. This means that with suitable corrosion protection, thin-gauge hot-rolled strip can substitute cold-rolled galvanized strip for a wide range of applications. Primetals Technologies has developed a solution type that is suitable for both wide and narrow hot-rolled-strip galvanizing. The first plants are already successfully operating at Wuppermann Bandstahl (Linz, Austria) and at Ornatube in Taiwan. Substantial cost savings can be achieved when the pickling section is incorporated into lines of this type. Galvanized coils from hot-strip galvanizing lines represent an excellent starting material for the downstream production of a wide range of sections, drawing parts and tubes for the construction, appliance and automotive industries.
- No need for annealing and cold rolling
- Highly compact plant layout and design
- Cost savings through in-line pickling as option
- Low operational and environmental expenditures
- Flexible on- and offline operation with induction heating
Fig.2- Electromagnetic strip vibration damper and crossbow corrector | Fig.3- Exit section on a continuous galvanizing line, Benxi Iron & Steel, PR China | Fig.4- Dynamic air knives Dynawipe
Electrotinning Lines and Tin-free Steel
Our electrolytic tin plating lines are designed to provide you with high plant performance and product quality. Our tin plating process allows for equal or differential strip coating. The coating performance is drastically improved by our tension leveler, installed upstream of the process tinning section. The thickness of tin layers is monitored and controlled through Primetals Technologies’ automation system. Tin-free steel (TFS) is less costly than tin plates, and boasts superior lacquer and paint adhesion, as well as strong resistance against corrosion.
- Optimized precleaning and cleaning design allows for strip cleaning at the fastest line speed possible for the tinning process
- Pickling section meets environmental regulations
- Tinning coating processes with soluble anodes MSA or PSA
- Insoluble anodes
- Induction or conduction
- Improved lacquer formulation reduces need for chemicals
- Integrated environmental solutions
- Strip flatness controlled before tinning process
- Process section designed for fast and efficient strip coating
- Increased yield and throughput capacity
- Optimization of utilities consumption
- Reproducible “in control” process technology
- Consistent product quality
- Environmental friendliness
- Continuous process development
Fig.1 - Tinning line tension leveler
Primetals Technologies has vast experience in upgrading and modernization of processing lines. With a systematic approach, we work closely with our customers to develop a tailored modernization concept based on their individual needs taking all boundary conditions fully into account. The solution may be purely electrical, automated, mechanical or a combination. Based on the selected concept, the modernization can be carried out in several steps or during a plant shutdown. Primetals Technologies’ experience minimizes downtimes and ensures a fast start-up and top quality.
Strip welding by Laser or Mash Lap depending on final application
Primetals Technologies introduces its most advanced laser welder performing welding and cutting using asolid laser source, dedicated to ultra high strength steels. This welding machine, called LW21L, provides a very high performance level for a wide range of grades.
For metallic coating lines, Primetals Technologies also offers the state of the art MashLap welding machine ranging from 0.1 to 5.0 mm.
To allow a good layer adhesion onto the strip surface, oil and fines are removed thanks to adequate cleaning definition in association with process technology. Thanks to the improved technology of different cleaning section designs (spray, “V” shape and electrolytic, vertical tank and electrolytic), our electrolytic cleaning section help you optimize the consumption of utilities and reduce waste.
Air knives with zinc coating gauge
Our zinc wiping solutions are adapted to the high-end application demand at a cost effective approach. The unique design enables to precisely control the coating thickness, longitudinally and transversally, for quality and cost efficiency. With complete closed loop control of the zinc coating in full automatic mode, Primetals Technologies Dynawipe air knives enable accurate coating of a wide range of strip gauges and widths with the most optimized zinc consumption.
Skin-pass mill and tension leveller
With more than 500 references around the world, our solution range encompasses skin-pass mills and tension levelers that cover all applications. With rolling force capacity ranging from 400 to 1,500 tons, skin-pass mill stands can be of two-high, four-high or six-high design – thus providing a best-in-class solution, whatever your application.
The Primetals Technologies range of tension levelers starts from 6.5 tons tension capacity up tp 35 tons.
Our coaters include all technological aspects, including mechanical, fluid, electrical and automation functions. This modular approach offers great benefits, and allows us to provide completely integrated solutions consisting of extensively preconfigured products, solutions and cycle services specifically tailored for galvanizing lines.
Single head or turret-type side trimmer
Primetals Technologies innovative side trimmers for metal coating are called ST21M. In turret or single head type, they can feature options, such as Dynamic Width Adjustment (DWA) and/or EdgeMon system. Our single-stand or turret or dual shifting scrap choppers SC21M ensure the highest quality cutting and strongest availability. The pertinent choice of drum diameter and number of knives ensures the longest running time available in the market. Close association of side trimmer and SC21 scrap chopper is a guarantee for a best scrap disposal and lowest cobble ratio.
With Primetals Technologies inline and real time measuring system for metallic coating lines, steel producers can not only determine mechanical properties (tensile and yield strength) but also steel magnetic behaviour in a non destructive way. The specific sensor head design and associated innovative signal processing ensure highest results guarantees.
SIAS® – automated surface inspection system
SIAS is the worldwide leading solution in surface quality control of exposed-quality galvanized products for the automotive industry. It detects and identifies critical defects, for deep-drawing applications such as fine slivers, holes or scratches and coating defects. The tiniest defects like arc spots, may be detected even at maximum speed. For critical applications in the automotive, packaging or appliance markets, SIAS® provides synthetic, highly accurate information on surface quality.
The TCOptimizer offers the means to secure the production by keeping an eye on all the signals of the whole metallurgical route (from casting to downstream process) and triggering just-in-time alarms against performance degradation regarding equipment conditions, process and product quality. TCOptimizer helps you also to better control your consummables (ex: reducing gas consumption by furnace temperature optimization) in order to reduce costs.
Condition monitoring system
With the inline measuring system for metalic coating lines, steel producers can determine mechanical properties (tensile and yield strength) in a non-destructive way. The process can be optimized effectively and quality can be guaranteed. PropertyMon continuously inspects the product, informs of any process deviations and avoids customer claims.
Fig.1- Multiroll tension leveller MTL21 | Fig.2- Roll coater | Fig.3- SIAS on a CGL
The efficient and uninterrupted production of high-quality value-added products in strip-processing lines can only be assured by the application of advanced automation and process-control systems. This is particularly true for seamlessly linked processing lines where the varying speeds of the individual plant facilities have to be optimized to ensure best product quality and maximum output.
Our portfolio of solutions includes the following systems and models
- The Advanced Pickling Set-Point Model (APM) for uniform pickling
- The Automatic Strip-Quality Detection System to gather and classify all quality data
- The Steel Quality Manager to document quality of discrete strip segments
- Adaptive Elongation Control to achieve closest elongation tolerances
- DynaWipe for fully automatic zinc thickness control
- Closed-Loop Galvannealing Process Control to control the iron content in galvannealed coatings
- And Fully Automatic Pickling Liquor Analysis and Control (FAPLAC) to ensure optimal pickling results
- Reproducible and consistently high product quality
- Higher product yields and output
- Full transparency of all process and quality-relevant data
- Reduced maintenance with automatic diagnostic systems
- Process simulation and thorough pretesting of entire automation system
- Fast line start-up
Tata Steel Ijmuiden, Netherlands
Type of plant
Continuous galvanizing line DVL3
Our hot-dip galvanizing line incorporates the latest developments in technology and automation for producing a wide range of top-quality products.