HEAVY ENGINEERING
toughcore ® steels are characterised by outstanding toughness( CVN, CTOD and Battelle) to the core, even at very low temperatures and for the largest plate thicknesses.“ Based on the significantly lower transition temperature of ductile to brittle fracture, applications can be achieved with substantially lower risk of brittle fracture. Even the heat-affected zone( HAZ) of welded structures features improved toughness to ensure the highest safety standards.” voestalpine states:“ Utilising the full potential of toughcore ® steels, you will step beyond current limitations and explore new environments such as extremely low Arctic temperature regions and highest pressures in the ultra-deep sea. Together we can realise fixed and floating offshore structures, pipelines, cranes and mining equipment under extreme application conditions.”
The company says that toughcore ® highstrength TMCP heavy plates with higher thickness and excellent toughness cannot be manufactured in any other production process. Penstock or machinery applications that require quenched and tempered( QT) steel can now be substituted by toughcore ® TMCP steel. Benefiting from the lower carbon content and the lower sensitivity to cold cracking, TMCP steel can be welded without preheating, at a lower rate of failure and with higher heat input.
NLMK Europe has recently launched Quard 550, another new grade in its abrasion resistant steel family. Available now in a thickness range between 6 and 40 mm, it has been made available to the market through an expanding network of offices and official dealers around the world. Since the announcement of its commercialisation, it has been used by numerous companies specialised in the mining industry. For manufacturers of mining equipment, it can be used directly in mining trucks or as a lining in the case of haul truck bodies, where it is effective on both the floor and sides. In buckets, Quard 550 is found in shrouds and cutting edges. Its stable form prevents distortion and other steel transformation. The R & D department of NLMK Clabecq, where Quard is produced, is working on the widening of the range.
The product adds to the existing NLMK Europe Quard range with nominal hardnesses of 400, 450 and 500 HB.“ As it benefits from slabs coming from its mother company, made with equipment using the most modern technology of steelmaking, it can produce on specific request steel plates with very high toughness at-40 ° C. It results in steel plates with a high workability, improving the efficiency of operations through accurate cutting and easy welding, in the workshop as well as in the field.”
Rail wagons
This year’ s winner of the international Swedish Steel Prize is Kiruna Wagon from Sweden. The prize is awarded for the company’ s innovative wagon solution, the Helix Dumper. Kiruna Wagon has used high-strength steel to develop a highly durable and far more efficient wagon solution than other ore wagons on the market.“ Kiruna Wagon has successfully updated a good idea and used high-strength steels to turn it into a brand new, superior wagon solution,” says Eva Petursson, Chairman of the Swedish Steel Prize jury and Head of SSAB’ s Strategic R & D.
Kiruna Wagon’ s Helix Dumper is a dumper wagon system for long-haul rail transport and efficient unloading of minerals. Use of advanced high-strength structural and wear-resistant steels made it possible to design lightweight wagons combined with a stationary Helix terminal for onthe-fly rotary unloading. The ingenious solution has an unloading speed of 25,000 t / h, which is twice that of other systems.
For the final design, both Strenx structural steel and Hardox wear-resistant steel were used in the wagon solution. When comparing with other systems, a complete unloading system for the Helix costs 1 / 7th of what a rotational wagon costs. Furthermore, the Helix uses parts of the potential energy of the ore to push the wagon forward as it unloads. This means no extra energy is required and there is much less dust with almost no noise.“ Our customer had found a small design that they wanted to make into a large dedicated wagon concept. There were many challenges to overcome, including how to achieve a carrying capacity of a 100 t payload, while keeping the wagon light,” explains Fredrik Kangas, Managing Director at Kiruna Wagon.
The design utilises high-strength steel extensively in the structure of the wagon as well as for the stiffeners around the wagon body and for the top rail of the wagon. Wear-resistant steel is used in the two arches at the offloading site.
“ The Helix Dumper is designed in a way that minimises wear, which was one reason we believe that our choice of materials was optimised,” adds Kangas.
Dragline chain
For some crews, the holy grail of dragline chain maintenance is a tough, reliable repair link that is also easy and safe to install and remove. With that goal in mind, Columbia Steel Product Engineer Charlie Dreixler has been working extensively on hoist and drag chain designs since 2010.“ We’ re on our fifth generation of mechanical repair link improvements,” says
Chain repairs can be safer and more efficient with Columbia Steel’ s patented EZ RigLok ® pinning system
Dreixler,“ and a year’ s worth of field trials in Wyoming and North Dakota have already convinced customers to place additional orders.”
Key to this repair link’ s success is Columbia’ s EZ RigLok ® hammerless, mechanical pin locking system.“ The system has also proven to be a faster, safer locking mechanism in many other Columbia Steel dragline products as well, like hoist links, swivel links, and clevises. The EZ RigLok repair link requires no welding or special tools, and needs just a standard 3 / 4 in breaker bar to install and remove.”
Dreixler notes that“ accelerated wear on hoist chain in the bucket rub rail area is a frequent cause of downtime – and a real test for any repair link. During our Wyoming field trial, the EZ RigLok repair link lasted for over seven months in a rub rail position.”
Last year, the commercial availability of the ProLink mechanical dragline chain link was announced. ESCO’ s ProLink mechanical dragline chain link is designed to reduce costs by extending the service life of a mine’ s hoist and drag chain. The product provides a hammerless and hot work-free installation and removal for rapid replacement in any strand location. This chain link can be rotated quickly into four different positions for increased duty cycles, lowering total operating costs.
“ These innovative breakthroughs enhance mine site efficiency by increasing uptime and extending the life of their rigging system,” said Austin Peterson, Global Product Manager at ESCO.
The ProLink mechanical dragline chain link is available in multiple sizes covering a range of dragline chains on the market today: 3 in, 3.5 in, 4 in, 4.5 in, and 5 in.“ In field trials in North America and Australia, some mines are reporting a change time as little as five minutes. Already the ProLink mechanical dragline chain link has clocked up to 40 % longer duty cycles, and shown up to 66 % less chain maintenance downtime.” IM
62 International Mining | JUNE 2017