Danieli & C. Officine Meccaniche S.p.a. (Micromill Project)
As part of its goal to find new solutions to enable companies to increase productivity while also lowering their energy consumption and other operating expenses, Danieli & C. Officine Meccaniche S.p.a. has developed many steel casting and rolling technologies, including using endless casting and rolling to enable steelmakers to reduce energy in reheating before the steel is rolled.
This is one of the main advantages of the Danieli micromill (MIDA) technology, which has created a 250,000 to 500,000 short ton per year production facility where liquid steel flows into the caster mold and the process continues until the finished products are ready for shipping. By comparison, traditional mini-mills cast semi-finished products, billets or thin slabs that are then cut at prescribed lengths and moved to a storage area to await further processing in the rolling mill.
Continuous and direct casting and rolling eliminates the need for semi-finished products, cooling, storage and reheating, as well as the need for cropping, which, along with eliminating multiple head and tail crops on the final products, maximizes product yield throughout the mill. Also, in an endless operation, with the caster and rolling mill located close to each other, there are more stable rolling conditions, which result in higher-quality finished products.
Based on its energy savings, which have been estimated at about 280 kilowatt hours per ton, and logistics advantages, Danieli estimates that MIDA could result in up to 5% product cost savings about $15 per ton as well as a 1-3% increase in yield and a $5 to $10 per ton reduction in operating cost compared with a traditional mini-mill. The technology also offers greater flexibility for production changes, enabling the steelmaker to deliver steel with a short lead time when their customer places an order.
Danieli & C. Officine Meccaniche S.p.a. (Universal Endless Project)
Danieli & C. Officini Meccaniche S.p.a. says that, for the first time ever, coil-to-coil and endless, thermo-mechanical and multi-phase, ultra-thin and thick products can be produced on a single production line, made possible by the companys new DUE® (Danieli Universal Endless) mill, which is the latest addition to Danielis Quality Strip Production (QSP) family of strip-quality, thin-slab-based steelmaking plants.
What makes DUE® different is that this thin-slab casting and rolling plant can unify, in a single production line, features that up to now have been achieved only by using either endless or coil-to-coil rolling modes in separate production lines. The new technology also eliminates the limiting factors of each of those types of line.
Its ability to produce slabs 110 mm thick after soft reduction, at speeds of more than 6 metres per minute, results in high productivity as it makes it possible to easily reach the mass flow conditions required for the full endless production mode that is necessary for effective production of ultra-thin-gauge steel.
Meanwhile, its ability also to provide the mill with slabs that are thicker than those produced in a traditional thin-slab caster allows the steelmaker to produce a wider mix of products, including low-, medium- and high-carbon, high-strength low alloy, peritectic, silicon, linepipe and advanced high-strength steel grades.
DUE® also results in both high production and high operational flexibility. Also, its tunnel furnace ensures temperature uniformity throughout the thickness, width and length of the slabs, both at the mill entry side of the mill and at the furnace exit, regardless of the casting speed.
While the overall furnace length is limited to about 80 metres from first to last roll, this still allows for the production of full coil weight in coil-to-coil mode.
DUE® covers the full spectrum of geometrical strip dimensions, ranging from 0.8 mm ultra-thin gauges produced in endless mode up to 25 mm thick strips. It also has low energy consumption and transformation cost thanks to its ability to utilize only an induction heater when required by the endless process and the ability to select the cheapest mode for each thickness.
Falk PLIs 3D laser metrology technology, which is focused on improving quality, productivity, throughput and reliability, and decreasing downtime, has been quickly replacing tight-wire and optical alignment in the metals industry. The technology has also been instrumental in the evolution of aerospace and automotive industries.
Implementing 3D laser metrology best practices has helped steelmakers to reduce caster outages by days, not hours, helping them to reduce caster segment replacement time by 75%. For example, it helped one continuous heat treatment line to eliminate strip track-off, enabling it to now run wider, thinner, harder material faster than before. It has also helped to reduce one companys HSM winding issues by over 50%.
Steelmakers using 3D laser metrology best practices have also been able to reduce and/or eliminate corner cracking issues when casting high-strength steel. It has also been able to help companies to reduce and/or eliminate long-standing shape issues in their hot rolling and cold rolling processes.
Falk first introduced this technology in 1998 with the first major installation being in 2000 at the former Ispat Inlands No. 1 slab caster straight mold conversion.
Water is a critical component of the steelmaking process. About 95% of the water used by steelmakers is recycled back to the source, but from the time the water enters the facility until it is returned to the source, Nalco technology helps mills to meet their safety, production and environmental goals.
The expertise of Nalco Water has also helped steel-producing companies to increase their steel production volumes while remaining in compliance with their discharge permits. Failure to comply with the limits of discharge permits could not only lead to daily fines of several thousands of dollars, but also potential shutdown, leading to loss of revenue and brand image.
Nalco Waters total water management approach involves a combination of equipment design and selection, operational changes and chemical treatment.
Its chemical approach uses a dual-function polymer technology that has been proven to be very effective in capturing and precipitating undesired elements. In a single process it treats the wastewater for the removal of mercury, zinc and other heavy metals or for effluent polishing.
Nalcos high-efficiency filtration technology also effectively mechanically removes a broad range of particulates, representing greater than 90% of the total suspended particulates in the wastewater. Nalco also utilizes a proprietary water modeling tool to simulate the water balance and its impact throughout the plant and to confirm the concentration of certain of the waters constituents.
By being proactive in their environmental stewardship, steelmakers can focus on what their mills are suited to do best produce steel efficiently and effectively as opposed to having to concentrate upon the management of water and wastewater.
With demand for higher-quality steel products increasing, along with the desire for more tailor-made steel grade solutions, shorter development times for new steel grades, and a greater ability for OEMs to swiftly respond to quality deviations, steelmakers realize they need to increase their product quality, process stability and flexibility, and production efficiency, especially related to the production of premium-grade products.
One way to do this is for steelmakers to look toward digitalization to improve their processes, as well as taking advantage of the latest equipment technologies, metallurgy and operational know-how to enable them to produce these higher-quality products.
To fill this need, Primetals Technologies developed its Through-Process Optimization (TPO) concept. It is an Industry 4.0 solution for the metals industry, designed to ensure accurate and stable control of all process parameters by using the digital interconnection of various process units.
Although Level 2 process models have existed for many years, there was no capability to connect one unit to another. TPO, however, is a comprehensive solution that optimizes the entire steel production process from the liquid phase through the finished product, providing quick and complete access to quality- and process-relevant data, a deep understanding of how a change in process parameters will affect the properties of products and the know-how to develop products quickly and successfully.
It does so through its Through-Process Quality Control (TPQC) system, which combines data and information with operational, metallurgical, quality assurance and process knowledge, and its Through-Process Know-How (TPKH) packages, where Primetals and its external consultants provide support on a wide range of topics, including plant operation, quality management, maintenance and end-customer qualification.
The TPQC system contains a basic set of rules that are complemented by additional customer-specific know-how rules to guide production. It also helps to ensure that desired product properties are achieved, and, in the event of deviations, TPQC supports operators and quality engineers with root cause analyses and automatically generated suggestions for corrective and compensational actions. Machine learning is used to implement data-based decision modules and algorithms to monitor trends and to introduce corrective actions.
Glenmount Global Solutions/SR-Instruments Oy/ArcelorMittal Global Research
The presence of roll-mark defects at the exit of cold-rolling tandem mills has long been a very costly problem for the steel industry, resulting in the need for steelmakers to reassign and downgrade all the affected coils.
The downgrading cost alone for cold rolled steel coils with roll marks produced by tandem mills serving the automotive market has been estimated to average about $1 million per year. The automotive industry has long demanded a zero-base defect tolerance from their steel suppliers. Mills also find it difficult to reassign these customer-specific coils.
The current practice of doing periodic manual inspection of coils to reveal the potential presence of roll marks has proven to be very costly to mills productivity and efficiency, with the high risk for delays and other manual inspection issues that are difficult to manage in the long term.
Ever since automatic surface inspection became available, companies have considered developing a technology that could automatically detect these roll marks, but the sensitivity of even the most modern automatic surface inspection systems did not allow satisfactory detection of these very-low-contrast defects. Scientists at ArcelorMittal Global Research partnered with SR-Instruments Oy to develop a new compact on-line sensor, which went through further research and development aided by two European Union funded R&D projects.
The result is a stand-alone, standardized fully automatic roll-mark detector system that is capable of operating in the cold-rolling mill exits of both tandem and temper mills, enabling steelmakers to improve their competitiveness. The system is robust and simple to install. It is fitted to the mill exit with optional integration equipment for maximum safety and easy maintenance and it requires very few integration inputs.
After the start-up, the system automatically starts to look for roll marks. Alarms and roll-mark images with location information are displayed on the user interface after detection. Also, a coil-by-coil database that is accessible over the network is created automatically.
This automatic roll-mark detector is being marketed in North America by systems integrator Glenmount Global Solutions.
TMEIC Corps TMdrive®-10e2-DP dual-purpose drive enables steelmakers to replace individual DC motors over time with new, more efficient AC motors. Suitable to power DC or AC motors, and intended for use in modernization projects where existing DC motors will be retained, it is based on TMEICs TMdrive® family of 10e2 inverters and its 10e2-DDC technology.
Steel Dynamics Inc decided to use this dual-purpose drive at its No. 1 galvanizing line in Butler, Indiana, when the company was no longer able to get parts for its discontinued existing drives and, in doing so, realized improvement in production, operational flexibility and efficiency. The new drive reduced the companys initial investment in new AC motors and its changeover outage time, while providing a future path for it to upgrade remaining DC motors to AC motors.
The TMdrive®-10e2-DP drive starts out as a standard AC drive, but four of the insulated gate bipolar transistor (IGBT) devices in the bridge are used for the DC armature, while one of the remaining two IGBT devices is used to control the DC field. Filtering has been added to both the armature and field circuits in an outboard auxiliary cabinet to smooth the output and to protect the existing motor from switching transients.
All the hardware associated with the DC application is in the auxiliary panel so that it could be discarded when the motor is changed to AC sometime in future. Also, new software is loaded to make this AC drive capable of controlling a DC motor.
The TMdrive®-10e2-DP drive provides a path to an all-AC line without having to replace the larger DC motors immediately. It also provides certain immediate benefits for the power system, including near unity power factor (even when controlling DC drives), low harmonics and improved efficiency. The concept has proven its value, given that the existing DC drives can be left untouched or upgraded as required.