Innovative Wearfacing/Reclamation Techniques

Abstract

Wear and tear of Bow) Mill - Crusher grinding Rolls and pulverized Fuel bends, very much depend on quartz (SiO,) particle size distribution and quartz content in Coal. In Indian coal, quartz is considered to be most important constituent causing wear and tear. Coal used in thermal power plants contain high ash which while being carried pneumatically in pulverized form causes extensive wear/ erosion on components viz. P F bends. Milfparts, Coal burner nozzle, orifice etc.

Many a times, it is observed that, wear parts are discarded even when the total weight loss in these vital, machinery components is only to extent of 10 to 15% That means, nearly 85 to 90% materials is scrapped and remetted again in foundries Similarly, single steel alloys, which are traditionally used to combat wear are not capable of withstanding devastating effect of abrasive wear when it is coupled with tension, compression, torque and shock leads Therefore, the metallurgist is compelled to design the material which balances interdependent properties viz hardness, toughness, and strength. There is a growing need now to conserve industrial goods/components by adopting latest technically and commercially viable Reclamation/Wearfacing Techniques This paper presents:-

1 Weld overlaying on metals/alloys, which are considered to have absolutely poor weldability, e.g. Bowl mill crusher, grinding rolls of Ni-hard Grade. IV. or chrome iron.

2 Composite wear plate concept, when a wearing part is subjected to both stress and abrasive wear, the same should be made of two alloys fully bonded together i.e. a strong, tough base metal and hard wear resistant overlay. Though, this is performed by employing conventional hard facing welding consumables regularly, the fact that composite wearplates offer not only just unmatched wear resistance property but also, it provides muscles on metals/machinery components, to combat wear very efficiently and economically.