Nama : Eldayadi Nefty R A2613101011Heat treatment
Nitridingnitriding surface hardening is a process withnitrogen to the surface elements of difusionsolution on metal/steel and cast iron feritik, bymeans of heating and holding the metal/steel andcast iron at temperatures below the criticaltemperature (between 500-590oC),for a period oftime in contact with a gas or liquid nitrogen.The entire steel and cast iron which canbe hardened and hard, must be in temper beforenitriding process is done, where the temperature ofthe tempering should be high enough to maintainthe stability of the structure of nitriding processes(nitriding temperature 100C above the minimum).
Application FactorsPrincipal reasons for nitridingare: To obtain high surface hardness To increase wear resistance and antigallingproperties to improve fatigue life To improve corrosion resistance (except forstainless steels) To obtain a surface that is resistant to the softeningeffect of heat at temperatures up to the nitridingtemperature
Introduction GAS NITRIDING is a case-hardening process wherebynitrogen is introduced into the surface of a solid ferrousalloy by holding the metal at a suitable temperature(below Ac1, for ferritic steels) in contact with anitrogenous gas, usually ammonia. Quenching is notrequired for the production of a hard case. The nitridingtemperature for all steels is between 495 and 565 C.The nitrogen source is usually Ammonia (NH3). Atthe nitriding temperature the ammonia dissociatesinto Nitrogen and Hydrogen.2NH3 ---> 2N + 3H2
Furnace and The nitrogen diffuses into the steel andhydrogen is exhausted. A typical nitriding setup is illustratedin Figure .
Data12 hours -> 0.12 to 0.20 mm24 hours -> 0.20 to 0.28 mm48 hours -> 0.28 to 0.38 mm72 hours -> 0.39 to 0.53 mm
White layer thickness may vary between 0.012 and 0.20 centimetre.which depends on nitriding time. The most commonly nitrided steelsare chromium-molybdenum alloy steels and Nitralloys. Surfacehardnesses of 55 HRC to 70 HRC can be achieved with case depthsvarying from 0.005 in to 0.020 in. Nitrided steels are very hard .
productEngine components for motorcycle, others :-steering gears-cylinder heads-cylinder linersmachine tools, other :- cutting tools (high speed steel)- rolling tools- drawing tools
conclusion- The process of hardening of the toughestamong other processes.- longer the addition of ammonia, the thickerlayers hardness on metal surfaces.- All thats good nitriding process for hardeningthe steel surface, corrosion resistance andother mechanical properties, but nitridingprocess using ammonia gas are betterhardness compared to other nitridingprocesses.- All kinds of nitriding process it is goodto change the surface hardnessof the steel and other mechanical propertiesof the resultant right ofthe nitriding process, depending on itsapplication to steel