Annealing is the process of bringing a piece of steel up to its critical temperature, and then letting it cool very, very slowly (many hours to cool to room temperature). This causes the crystalline structure of the steel to become all pearlite/cementite/ferrite (depending on the carbon content). All these structures are extremely soft; the annealed condition represents about the softest state that steel can get without being heated to forging temperature.
Annealed steel really is very soft and can be cold forged somewhat. It grinds "like butter" (a length of bar stock could easily be bent in two along its narrow axis with your bare hands, and with a vise, it can also be quite easily bent along its widest dimension as well). This makes it very easy to form the steel to shape via grinding or forging.
After you grind or forge the bar to shape, you should perform a related process to annealing called "normalizing". There's not a lot of difference between annealing and normalizing. In normalizing, the goal is to relieve stresses and more importantly, to ensure a consistent and fine grain size rather than to soften the metal, so the slow cool isn't quite as critical for normalizing. The grinding and or heating/cooling and hammering performed during the shaping of the blade tends to induces stresses in the blade. Relieving work/heating induced stresses through normalization helps prevent or reduce the amount of warpage when you harden the blade, and refining the grain helps produce stronger blades that hold a better edge. When normalization is done, you can perform the hardening procedure - you heat the steel up to its critical temperature again, but this time, instead of letting it cool slowly, you quench it quickly in a quench medium (this could be water, brine, oil, or even air, depending on the type of steel you use) so that it cools very quickly. This causes the crystalline structure to re-arrange into a different form called martensite, which is an extremely hard form of steel capable of holding a keen edge.
Now although you relieved stresses prior to hardening, the quench procedure tends to induces new stresses of its own, so a subsequent tempering draw or the reheating of the blade to a relatively low temperature (well below red hot) results in stress relief and the decomposition of some of the martensite into another form called troosite which is slightly less hard, but much tougher. The blade thus becomes less brittle and gains more "spring". So you see that in addition to the usual heat-treating process of hardening and the subsequent drawing of temper, annealing and normalization can play an important role in the creation of a fine blade.
Annealing is a slow cooling, whereas quenching is a rapid cool.
For steel, quenching is used to form martensite whereas annealing is used to form bainite, pearlite, and ferrite.
See the Web Links to the left for more information about tempering and annealing.
what is the difference between anealing and tempering
Annealing. Heat from 1010oC to 1120oC and cool rapidly in air or water. The best corrosion resistance is obtained when the final annealing is above 1070oC and cooling is rapid.
There are three stages in the annealing process. The first stage is when a metal is heated up and it is called the recovery stage. The second stage is called recrystallization and the third stage is called gain growth. Each stage represents a higher temperature in the annealing process.
The malleability is improved by annealing.
140 to 160 degree Celsius
What is the difference between herds and packs?
spherodizing, normalizing, full annealing, process annealing, and stress relief
can we reduce the heat treatment time in carbon steel through normalizing instead of annealing?
The main difference between full annealing and normalizing is that fully annealed parts are uniform in softness (and machinablilty) throughout the entire part; since the entire part is exposed to the controlled furnace cooling. In the case of the normalized part, depending on the part geometry, the cooling is non-uniform resulting in non-uniform material properties across the part. This may not be desirable if further machining is desired, since it makes the machining job somewhat unpredictable. In such a case it is better to do full annealing.
Annealing and Sintering are the same processes.
In annealing you heat the material to a very high temperature (In case of Steel above the upper transformation temperature), hold it and then slowly cool it in the furnace atmosphere itself. This makes the grain size coarse. Contrary to this, in normalizing you heat the ferrous material (as it is only applicable to ferrous materials) and remove it from furnace and let it cool in the air. So the material becomes hard. The reason for this being you get a much refined fine grain structure.
The annealing temperature for this alloy is between 800 and 1200 F.
Normalizing Is a heat treatment process (predominantly used on Steels) It makes the material softer but does not produce the uniform material properties of annealing. A material is normalized by heating it to a specific temperature and then letting the material cool to room temperature outside of the oven. This refines the grain size and improves the uniformity of microstructure and properties of hot rolled steel. Normalizing is used in some in the production of large forgings such as: railroad wheels and axles and on some bar products. The process is less expensive than annealing.
Normalizing Is a heat treatment process (predominantly used on Steels) It makes the material softer but does not produce the uniform material properties of annealing. A material is normalized by heating it to a specific temperature and then letting the material cool to room temperature outside of the oven. This refines the grain size and improves the uniformity of microstructure and properties of hot rolled steel. Normalizing is used in some in the production of large forgings such as: railroad wheels and axles and on some bar products. The process is less expensive than annealing.
annealing for steels
water should be used for narrow parts like sheet or else high amount of residual stresses are made in the part.
Normalizing nutritional status starts with a nutritional assessment.
Full annealing process consists of three steps. First step is heating the steel component to above upper critical temperature by 30 to 50 deg c, after suffciant soaking time parts will be cooled very slowly in the furnace. Where as for ISo Thermal annealing parts will be heated above upper critical temperature by 30 to 50 deg c, after suffciant soaking time parts will be transfered to intermediate temprature( Below the lower critical temperature) and allow to equalise the temperature then cool in air to Room temperature