Incorrect application of hardfacing products on crushing equipment at sugar mills can be detrimental both to the equipment and to crushing efficiencies, says Afrox’s Kim Brightwell, business manager for welding consumables.
Hardfacing is a metalworking process where harder or tougher material is welded to a base metal and generally takes the form of specialised electrodes for arc welding or flux cored wires for continuous welding. Hardfacing may be applied to a new part during its production, or it may be used to restore a worn-down surface.
Hardfacing by arc welding is a surfacing operation to extend the service life of industrial components, pre-emptively on new components, or as part of a maintenance programme. The significant savings in machine downtime and production costs that can be achieved has meant that this process has been adopted across many industries such as steel, cement, mining, petrochemical, power, sugar cane and food. Extensive research has resulted in the development of a wide range of alloys and welding procedures.
“In the sugar industry, when repairing crushing hammers and cane knives it is very important to use the correct procedures to ensure that the correct wear properties and lifespan are achieved,” says Brightwell. “For instance, amperage that is too high during welding can reduce the hardness of the weld deposit, in turn reducing wear resistance and compromising the life of the component. Obtaining the correct wear properties and profiles can also have a dramatic influence on the efficiency of the crushing process by improving the throughput of the crushing mill.”
He says Afrox’s team of welding specialists is available to assist sugar mills to optimise the use of hardfacing products.
“In many cases our team members have been able to improve the life of the crushing parts, as well as reducing maintenance costs, simply by assisting mills to use the right products in the right way.”
Afrox’s hardfacing products have a broad spectrum of application in sugar mills — particularly the CR70 and Duracor 59 which were both developed specifically for the sugar industry by Afrox almost 30 years ago.
Afrox CR70 deposits a tough eutectic of austenite and metal carbide that can withstand impact at medium loads under abrasive conditions. The weld metal has a hardness of approximately 550 HV (52 HRC), which it can retain up to 400°C.
Duracor 59-O is suitable for the hardfacing of sugar cane hammers and knives, mining machinery, buckets, dipper teeth, pulveriser rings, coal crushers and other parts subject to severe abrasive wear.
Afrox is the leading supplier of these products to both the South African market and to other African states, including Mauritius, as well as to Indonesia, India and South America.