Although it might seem like a relic of the 1970s, graffiti remains a common eyesore and source of damage, frustration, and remediation costs among industrial and transportation sectors.
At the request of a customer for anti-graffiti steel, ArcelorMittal Dofasco (AMD) collaborated with sister company ArcelorMittal Europe to transfer anti-graffiti formulations pioneered in Europe to North America. AMD was able to work with the local division of the same paint supplier to have TagTough coating formulated and produced at AMD in Hamilton, Ontario, southwest of Toronto.
Within a year, AMD arranged customer trials that were quickly approved. The full coating and substrate system was launched in North America in October 2015 with an accelerated time to market performance: two years from the conception stage to the commercial roll-out.
TagTough steel features a factory applied coating that is difficult to deface with graffiti and washes easily. With TagTough, vandals find it challenging to apply their paints to the surface. Painting TagTough coatings requires more time and more paint, which often causes the paint to sag. Even if taggers are persistent, in most cases TagTough steel is easily cleaned using only a pressure washer.
TagTough is a three-coat, factory-applied prepainted steel comprising a corrosion-inhibiting primer, a PVDF color base coat, and a fluoropolymer-based clear coat. The graffiti-resistant clear coat works as a protective barrier against most graffiti materials, including spray paints and markers. The performances of the color base coat remains unaffected by the graffiti paint and the cleaning operation.
TagTough combines polyvinylidine diflouride (PVDF) and fluoropolymer coating formulations making it highly corrosion and weather resistant. Fluropolymers, like the common Teflon, polytetrafluoroethylene, are highly inert.
Originally developed at ArcelorMittal in Europe, the technology was transferred to ArcelorMittal Dofasco and trials were conducted at the Hamilton Research and Development facility.
Shedding weight while maintaining strength to insure safety and durability has been the overarching challenge in automobile design for years. The goals seem mutually exclusive and nowhere more so than in models such as the Chrysler Pacifica, a mainstream, high-volume family vehicle.
ArcelorMittals tailored blanks group (AMTB) has worked with FCA US LLC and Magna Internationals Cosma International operating group since 2012, and most recently identified the side structure of the vehicles body-in-white specifically the door ring and b-pillar as the area offering the greatest opportunity for weight reduction and improved safety performance. After 36 months, 2,000 engineering hours, and about 300 design iterations, the team agreed on one central concept: the worlds first five-piece, hot-stamped, laser-welded door ring and b-pillar.
The key, says AMTB, was finding the balance of ridged high-strength steel and more pliable energy absorption material that would allow the body of the vehicle to manage crash energies in small-offset and side-impact collisions without requiring a significant change in the overall weight of the vehicle. The solution? A five-piece door ring and b-pillar innovation that first appeared in March 2016 in the 2017 Chrysler Pacifica.
To address the production needs for that vehicle and allow for production expansion to meet additional demand from other automakers, ArcelorMittal invested heavily in the development of a dedicated, state-of-the-art processing facility in Woodstock, Ontario. Opened in 2015, the facility can produce more than 2-million hot-stamped laser-welded blanks using two continuous ablation and welding systems.
Using laser ablation, the company was able to combine two high-strength steel grades Usibor, a hot-stamping grade that supports weight reduction in advanced shapes that require higher tensile strength, and Ductibor, an energy-absorbing grade designed specifically to complement Usibor in hot-stamping applications and offer ductility to better manage the crash energies. The application marks the first time these two steels were used together in North America.
Arkansas Steel Processing
Pipe and tube strength levels continue to increase from grade X70 to grade X80, with the next generation of grade X100 already in development. Along with that has come a growing demand for new coil-slitting capability to handle heavier, thicker, and stronger coil steels.
Arkansas Steel Processing (ASP) has developed a five-cut slitting line that it claims is unique among North American service centers. The company has been cutting steel on the line since late 2016 and says initial response from customers has been positive.
It comes as no surprise to industry insiders that coils shipped for slitting are not always the flattest and smoothest. Nor do they need to be. Center buckle is irrelevant for strips measuring just a few inches. ASPs objective was to slit the heaviest, thickest, strongest material available in coil on a high-production basis.
By offering a heavy-tension leveler on a slitter, which is new in North American service centers, Arkansas says it can now supply flatter slit steel and increase productivity in high-volume stamping and roll-forming applications. ASP is targeting wider cuts where the tension leveler provides a competitive advantage. The company anticipates that the new line will meet the needs of the pipe and tube market over the next 10 years.
The line is capable of slitting up to 5/8-inch Grade X100 with five cuts. The tension leveler, within the slitting line, can handle up to ¼-inch Grade X60 and improve shape. To avoid the potential of surface issues, the slitting line features all alternating-current, high-torque, vector drives with excellent speed and torque control.
The ability to handle 100,000-pound coils, the largest in a North American service center, increases productivity, reduces changeover and splices in tubing, and decreases scrap generation in heavy stamping and roll-forming.
Huge heavy things that roll such as steel coils are difficult to secure for transport. And despite their size and weight, they are surprisingly fragile, requiring specialized handling in rail, truck, or marine transport.
Conventional shipping leaves coils exposed to excessive handling, damage, and the elements. Customers are subject to unpredictable sailing schedules, long transit times, and limited ports of call. Existing container shipping also incurs the difficulties of loading and unloading, and the instability of costly and environmentally unfriendly skids. Wood blocking and bracing is of variable stability and reliability, and even in the best case is a single-use solution.
Coil-Tainers objective was to develop a fit-for-purpose coil pallet that would fit in a standard shipping container eliminating expensive and environmentally unfriendly packaging and wood usage. The coil pallet can hold up to 25 tonnes of coil. The ability to secure coils in a standard box container means more reliable and efficient shipping because the load is in the mainstream of containerized cargo and can go on any ship to any port which is not the case with specialized handling in bulk haulers.
The company began discussions with various parties in 1997, developed the prototype, tested the concept, incorporated the following year and handled its first shipment with Trefel Arbed from Antwerp to Chester, Pa. in March of 1999.
Growth has been strong with 35,000 pallets now in service worldwide.
In 2016, Coil-Tainer signed a contract with a company that is bringing a moth-balled steel mill in Bahrain back into service. Since there is little wood available in the desert country, the Coil-Tainer pallet was key to deliver coils to global markets. After 16 years of only handling steel coils, Coil-Tainer also branched out last year to add aluminum and even titanium.
Timken Steel Corporation
Traditionally, existing steel cleanness measurements conducted throughout the industry fail to provide information that directly correlates with application performance.
Conventional processes do not measure enough area to provide the statistical detail to determine whether critically sized inclusions are present in a component. Such methods may underestimate the likelihood of flaws that can impact fatigue performance.
Realizing a need for improvement, TimkenSteel developed what it calls its Ultrapremium practices, an approach which measures and certifies results using automated scanning electron microscopy (SEM) with energy-dispersive x-ray spectroscopy (EDS) capability. The approach allows rapid inspection of a larger area, providing improved understanding of the overall inclusion population.
This results in more meaningful cleanness metrics relevant to component design, allowing customers to easily determine the probability of critically sized inclusions. That, in turn, means Ultrapremium steels can provide improved power density, longer fatigue life and longer service life over other types of steel.
TimkenSteel began developing its Ultrapremium steels approximately one year before commercially marketing the materials in 2016. The companys existing Parapremium melt practices resulted in the development of a higher-quality ASM2304 industry standard.
Ultrapremium processing can be applied to most grades of steel and dramatically lowers oxide inclusions over competing processes. The result is optimum performance and longer life, without changing the customer's steel specifications or manufacturing practices.
Ultrapremium steels are best suited for highly stressed, heavily loaded, fatigue-sensitive, engineered components such as gears and bearings.
Testing results prove Ultrapremium steels are significantly cleaner than domestic special bar quality (SBQ), bearing-quality steels and on par with vacuum arc re-melted steels.