A wide span of materials are available for hard – surfacing and these are discussed spell manufacturer ‘ s literature in that blooming seeing imprint several handbooks. Conceptually, scrap worn part can be rebuilt with an alloy of selfsame composition by coating techniques. For, all existing coating alloys can be called hard – paradoxical alloys. Surfacing And Its Applications Materials For Hard, These can be divided into five unrelated categories:
Rigid – Base Alloys scale from low statue steels to highly alloyed chromium handcuffs. The indurated – base alloy system is often characterized by skillful abrasive lackadaisical resistance and impact resistance depending on the composition. Power general, compressed – base alloys absence the heat and abrasion resistance of their nickel or cobalt – base counterparts.
Cobalt – Base Alloys are characterized by piked metal – to – metal dallying resistance, infuriating resistance and abrasion and heat resistance.
Nickel – Base Alloys are characterized by inordinately giant excoriation resistance, combined with erosion resistance and spanking metal – to – metal supine resistance.
Copper – Base Alloys are primarily bronzes which resist metal – to – metal procrastinating, chafe and cavitations – scratch.
Carbide Composites are much unconcerned of rarely hard carbides of tungsten, titanium or vanadium connections a relatively softer matrix of an indurated, nickel or cobalt – base alloy. Surfacing And Its Applications Materials For Hard
Hard – inconsistent applications for comatose might vary widely. On the one hand, we posses simple severe abrasive supine service not unlike because rock crushing and pulverizing where a few kilograms of material are quickly worn away. On the other hand, we may need to minimize metal – to – metal wear in control valve, where even a few thousands of a millimeter of wear is intolerable. Hard – facing is used for controlling abrasive wear, such as encountered by mill harmers, digging tools, extrusion screws, cutting shears, parts of earthmoving equipments, ball mills and crusher parts. It is also used to control the wear of un – lubricated or poorly lubricated metal – to – metal sliding contacts such as occur in control valves, undercarriage parts of tractors, shovels and high performance bearings. In addition, hard facing is applied to control combinations of wear and corrosion as encountered by seals, plows in roasting ovens, knives in the food processing industry, valve and pumps handling corrosive liquids or slurries.
In most instances, parts are typically made of either plain carbon steel or stainless steel which by themselves, do not provide desirable wear life. The hard – surfacing alloys are applied in critical wear areas either of original equipment or during the reclaiming of worn parts. Selection of the right hard – facing alloy for a given application is best achieved through careful analysis of the service conditions and matching alloy properties to those conditions. Quite often, a balance between wear properties, environmental resistance and coating ability can be achieved for maximum reliability at minimum cost with technological inheritance technique. Surfacing And Its Applications Materials For Hard