TECHNOLOGY
REFRACTORY BRICKMAKER BENEFITS FROM NEW DEVELOPMENT IN REPAIR MATERIAL FOR KNEADER ROTORS
will resist the abrasive nature of the alumina, magnesia and zirconia and keep the kneader in service for longer. Previously, the service technicians used
a high-performance nano-alloy as the wearfacing coating for this application. Its nano-scale microstructure resists abrasion from the fine powders being processed. However, the alloy is relatively costly and not always easy to obtain. Therefore, when EnDOtec 6070N became available as a flux-cored welding wire, the team saw an opportunity to use it. Not only is the new wire more
competitively priced than the original material, but it also has extremely high hardness and wear resistance. That means it could potentially increase component life and extend the maintenance intervals.
N
ew developments in materials have enabled production of an ultra-hard wearfacing alloy in
the form of a welding wire. Enrique Matey, Castolin Eutectic’s Global Product Manager Welding Consumables, shares with Welding World the results from a manufacturer of refractory bricks that is evaluating the material. Industrial companies can improve
performance by using the latest developments in materials and technology when they’re introduced to the market. However, the critical first step is testing and evaluation so that they can be certain that a new product achieves its promise. One example is a producer of refractory
bricks that are used for lining industrial furnaces and kilns. Following a successful trial, it has adopted the recently-launched EnDOtec 6070N welding wire for regular maintenance of its kneading machine. The kneading machine is essential to production and combines the required materials as fine powders and mixes
them into clay. Once the clay is evenly mixed, it is moulded into bricks and other elements before being fired in a kiln.
Heavy abrasion Refractory bricks achieve high temperature resistance thanks to a high content of ceramic materials such as alumina, magnesia and zirconia. The challenge when processing these is that they are extremely hard and abrasive, which leads to heavy surface wear and loss of material on the steel rotors that turn and fold the clay. This is particularly true on the leading edges, that experience high forces. As a result of losing this material,
the kneader becomes less efficient over time. Typically, the manufacturer finds that its rotors lose around 4 kg in weight every month. To overcome this, it schedules regular
service outages to apply a wearfacing coating based on an ultra-hard material. Not only does this return the rotors to their original dimensions, but the wearfacing
www.awd.org.uk WeldingWorld1 / 41
Rotor repair The kneading rotors are approximately 300 mm in diameter and 500 mm in length. During an initial visit, a welding technician applied approximately 4 kg of a wearfacing coating based on 6070N to the leading edge of the rotors. They also rebuilt areas of the rotor that had experienced more limited wear with a high-strength steel.
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