Stronger and lighter vehicle bodies can equate to profitability
Wear-resistant and high-strength steels (HSS) enable the development of lightweight and strong bodies, which translates into financial savings and less CO2 emissions, according to specialised steel company SSAB
Trucks, tippers, trailers, mixers, concrete pumps, and other equipment used on a construction site handle various types of abrasive material and load. They should be designed for robustness and durability to withstand their tough working conditions, with the minimum manufacturing and operating costs.
The conventional approach employed by bodybuilders has been to build the body and the chassis with thick mild steel to handle tough conditions. To achieve the required robustness, tippers manufacturers, for example, tend to use stiffeners on top of thick, heavy and poor performance steel. While stiffeners give the appearance of robustness, it is counterproductive. It makes the vehicle weak and inefficient due to its high mass and poor steel properties.
The better approach, according to Ozgur Yalcin, area sales manager of Nordic and US-based specialised steel company SSAB, is to opt for wear-resistant and high-strength steels (HSS), which enables the development of lightweight and strong bodies and translates into financial savings and less CO2 emissions.
“High strength steels have been adopted by manufacturers and construction companies for many years in the Middle East. A good example of this application is the multipurpose U-shaped tipper made of SSAB’s tough steel. It is stronger, lighter and more cost-effective to build and operate,” says Yalcin.
Ozgur Yalcin, area sales manager, SSAB
Since establishing its regional office and stock area in the UAE in 2008, SSAB has expanded its offerings to include high strength, high performance steels, quality certifications for their applications and a one-stop shop to order wear parts. The company’s two main brands are the Hardox® wear plate and Strenx™ performance steel.
Hardox® wear plate is a hard and tough steel for aggressive environments. It has hardness ranging from 350HBW to 700HBW, thickness from 0.7mm to 160mm and width up to 3.35m. It is also available as tubes and round bars. Strenx™ performance steel is a high strength, high performance steel for load carrying structures such as chassis, cross-members and booms of cranes. Strenx has thicknesses ranging from 0.7mm to 160mm and yield strengths ranging from 600 to 1300 MPa. It is available as hot-rolled plates, coils, sheets, cold-rolled sheets, tubes and open profiles.
“Hardox’s performance is a result of its production process, which includes a state-of-the-art metallurgical cleaning process and a unique hardening process, resulting in wear plates with outstanding hardness, toughness and workshop friendliness. Hardox is hard through and through, from the surface deep down to its core, with no weak link in the chain,” says Yalcin.
SSAB’s brand program which represents quality certifications for applications that use Hardox wear plate and Strenx performance steel are called ‘Hardox In My Body™ ’ and ‘My Inner Strenx™’, respectively. Hardox Wearparts™ is a one-stop-wear shop, an international network for manufacturers of high quality wear parts and services.
Murat Kozan, marketing manager, MENA, SSAB, explains: “Having ‘Hardox In My Body™’ and ‘My Inner Strenx™’ logos on a product verifies that it's a first-class product that delivers unsurpassed wear resistance and impact strength. Applications with these signs attached have passed our strict quality control and are approved as a premium products by the SSAB board. Specialists within wear and structural technology carefully analyze each application regarding welding quality, manufacturing process and design. Each sign has a unique ID that is traceable and can secure the origin and material. All members are thoroughly assessed to earn the right to display their sticker."
Currently, SSAB has four local Hardox In My Body™ certified partners namely Gorica industries, Al Shirawi Equipments, Bion Industrial, and Qatarian Vehicles Structure Factory. Bion is also a My Inner Strenx™ brand program member.
"We are always receiving applications and new products which are always under review or certification process," says Kozan.
Yalcin points out three main benefits of using HSS for construction companies: they include lightness, strength and cost-effectiveness of applications, and their combination increases payload, fuel economy, driver performance, service lifetime and maintains the value of the vehicles in the second-hand market.
He elaborates: “Optimised designs utilizing thinner dimensions of HSS can reduce the weight of the body and the chassis of the equipment, drastically. For example, a tipper body weight can be decreased up to 45% with a Hardox® 450 wear plate, and the payload increased by by up to 5 tons. As a result, it is possible to achieve fewer trips for the same work and have less empty truck weight which are both significantly to achieve up to 12% fuel improvement and save on other operating costs such as tires, maintenance and fleet management. Less weight also means better maneuverability which gives the driver the opportunity to perform better and contributes to increased road safety.”
Wear comes in different forms such as shocks, jolts, bangs, nicks and jabs, day after day, and each has a different impact on the service life of the equipment. The most common wear types are sliding wear and impact wear that scratch and scrap the material.
“The hardness of HSS minimizes wear by making it difficult for abrasive materials to scratch or scrape the material, thus increasing the wear performance and lifetime of the equipment. A Hardox 450® wear plate gives up to four times longer service lifetime compared to mild steel especially in tipper sidewalls and floor. Hardness is what gives Hardox wear plate its unique wear resistance,” says Yalcin.
In the process of maximizing equipment utilization, construction companies face unexpected equipment breakdowns, which can affect their profitability. They need to be careful about the wear plate’s resistance against dents, cracks and crack propagation from the impact of rocks against the floor and sides of the tipper body. This ability is named toughness.
“Toughness is the definitive difference between Hardox wear plate and regular abrasion resistant steel. Hardox wear plate is produced in a carefully controlled steelmaking process to deliver the best combination of high hardness and high toughness. Hardox® 450 can take heavy blows without becoming deformed, which means there’s less or no need to restrain the movement on the sidewalls and in the structural framework under the floor of a tipper body. It enables to reduce or even remove heavy and complex stiffeners entirely. Testing and calculations have shown that a flexible tipper body structure reduces the depth of dents and improves resistance to cracking. By removing the stiffeners, the entire wear plate can absorb shock, making the best use of the steel’s properties. An HSS such as Hardox® wear plate is the ideal match for a flexible tipper body design,” he explains.
Hardox® 450 wear plate can withstand heavy impact without permanent deformation or cracking in tipper and trailer applications
The abovementioned benefits extend to manufacturers and bodybuilders in terms of lower costs, increased profit, and easier operation. Reducing the sheet thickness which means using less steel, gives a substantial cost reduction in processing. Using thinner gauges in the workshop allows the cost for cutting, bending and welding to be reduced. HSS material can be processed by the same kind of machinery and technology, such as laser cutting, used for conventional mild steel, and the manufacturer will be able to decrease the cutting time due to the thinner gauge.
“Welding on thinner material gives, in most cases, the largest cost reduction due to the reduction of consumables and the opportunity to increase the welding speed. Bending of profiles in HSS generally does not require greater force than a profile in a thicker gauge made from conventional steel,” says Yalcin.
Yalcin points out that when evaluating the financial benefits it is important to take all aspects affecting the overall production economy into account.
“Comparing the price level per ton for different steel grades alone does not give a true picture of the manufacturing costs. Even if the price per ton is higher for HSS, less steel consumed due to the weight reduction lowers the total cost significantly. Design improvements are also very important for financial benefits. For example, by removing the stiffeners, a tipper body built with Hardox 450 needs fewer number of pre-manufactured pieces. This reduces overall bending, welding, cutting production cost significantly compared to a tipper body in conventional design with mild steel. It also provides shorter lead times and reduced risk of production issues that cause expensive secondary costs for repairs, corrections and inspections. Introducing HSS with good bendability may also allow the number of welds to be reduced,” says Yalcin.
SSAB offers extensive service and support for the Middle East region through its head office and stock area in Sharjah, UAE, and Hardox Wearparts™ centers located across the GCC, Lebanon and Jordan.
“Our support and services cover the entire development chain, from structural design to choice of material, welding and joining, fatigue and wear analyses, forming simulations, workshop support, production efficiency recommendations, and training," says Yalcin.