normalized (surface)
English translation: normalization is a heat treatment in which the piece temperature...
| 20:29 Jul 28, 2004 |
| English language (monolingual) [PRO] Tech/Engineering - Medical: Instruments | |||||||
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|  Selected response from: Clauwolf Local time: 01:06 | ||||||
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| 4 +7 | normalization is a heat treatment in which the piece temperature... |
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| 4 | tapered in steps |
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peer agreement (net): +7normalization is a heat treatment in which the piece temperature... Explanation: ...goes over the transformation point (steel), and after that the cooling is made naturally in open air, without any external changes (like some type of ventilation) -------------------------------------------------- Note added at 24 mins (2004-07-28 20:53:18 GMT) -------------------------------------------------- You can see the basic heat treatment definitions for annealing and normalizing in the following site: 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 ... swordforum.com/forge/annealing.html - 7k - Em cache - Páginas Semelhantes -------------------------------------------------- Note added at 25 mins (2004-07-28 20:54:56 GMT) -------------------------------------------------- errata: normalization, not normalizing -------------------------------------------------- Note added at 34 mins (2004-07-28 21:03:30 GMT) -------------------------------------------------- From the site above: 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. |
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