I did want to lay to rest some of the Damascus Steel rumors that I've heard. First off, lets say what Damascus is. Damascus steel is only called Damascus because that is where the Crusaders first saw swords and knives that had a watery pattern in the blades. This was originally called "wootz" steel and was manufactured in India, where you can still see the remains of many forges built to face monsoon winds. The exact process to make true wootz was lost, though some French scientist (at least I think he was French) found a way to produce a reasonable facsimile. By taking steel and melting it down and adding a substance with sufficient carbon (like charcoal) to the liquid, the carbon would combine with the steel in the crucible. Then they'd pour it out and wait for it to solidify in little buttons of wootz, which they'd forge into billets (bars). By folding the metal over on itself the metal would form a wavy, watery pattern due to the two differing levels of carbonated metal. The fewer folds the more the pattern was pronounced, the more folds the lesser you would be able to see unless you were up close.
This part is where the legends came in. The folding process, which is called pattern forge welding, was originally done to purify the metal. By folding the metal and drawing it back out, you could work the impurities out of the metal. Now-a-days even the most garbage piece of rebar is of better quality steel than most of the middle ages swords. However, you still hear stories of swords that were folded 10,000 times and can cut through other swords. Metal will always retain the same qualities, so unless that metal could cut through another sword with only 1 fold, it can't do it with a million. By the way, here is a math fact for you. How many folds does it take to make a sword or a knife with 1,000,000 layers? Observe:

Fold 1 = 2 layers
Fold 2 = 4 layers
Fold 3 = 8 layers
Fold 4 = 16 layers
and so on until
Fold 20 = 1,048,576 layers of metal

So you see, it really wouldn't be impossible to create a piece of that complexity.

After the metal has been forged into the desired shape, edged, and polished, it would be dipped in an acidic bath that would react differently between the two levels of carbon in the metal, darkening one and shining the other. Some have also found a way to make Damascusized steel by using cable. Here is a pic.


And that is Damascus Steel.

Disclaimer: This is what I did. I'm not telling you to run out and do this, so if you get hurt, I'm not taking any responsibility. Please, in what ever you do but most especially forging, SAFETY FIRST.

Now, here's how I built my first forge. I went to Wal-Mart and purchased a cheap grill. I bought the table top model because I am impatient, but in hind sight, I should have gotten one with legs that would have put the bowl around waist height. I used a reciprocating saw to cut into the metal on the front, enough so that I could bend the metal back on the top and bottom. This created a large space where I could insert the metal I was working on. Lowes (not too sure about Home Depot) carries furnace cement, which is rated up to, I think, two or three thousand degrees. I ended up using about four of the little containers in order to completely cover the inside of the bowl and the top. Important note: If you are dead set to repeat this project, make sure that you put a thin layer on the grill and let it dry before applying the next coat. This will take a full night to properly cure, but it beats super heating a semi-liquid trapped just below the thin crust of cement. For those who are not physics buffs, this will cause the aforementioned semi-liquid furnace cement to do the same thing your radiator does on your car when you remove the cap after driving. Hot liquid everywhere.
For an air source, I purchased a hand bellows from Lowes. For my beginning stages, this works fine, but I plan on using a small motorized fan and a pipe to force air in from underneath. Another important note. Do not use any form of galvanized metal!!! Galvanized metal, and piping, when heated exudes a poisonous gas. Only use black iron, this also extends to the metal you are forging. I purchased a three pound blacksmith's hammer from Lowes, a bag of wood charcoal and some gloves. The wood charcoal is important, since regular cooking charcoal cannot get hot enough for forge work. Lastly, there was the anvil. Here is a little info on anvils. If you tap the horn of the anvil with a hammer, if it makes a lovely "riiiiiiiiiing" sound then it is probably steel, if the sound is more hollow, it's cast iron. If you can get a steel anvil, more power to you. They are pricey. Cast iron will work, though won't last as long as steel, for a fraction of the price.
As for the metal, the first few dozen times you try to forge something it will always come out the same, a twisted mess. Don't think that you need to find the perfect bar of stainless steel to work on out of the gate. Lowes sells re bar, and the crappiest piece of re bar (believe it or not) is of a higher quality steel than the best made sword of the middle ages.

Author: jeff bowerman
Tempering is the process of making steel tough after it has been hardened, so that it will hold a cutting edge and resist cracking. Tempering makes the grain finer and the metal stronger. It does not affect the hardness, but increases the elastic limit and reduces the brittleness of the steel. In that tempering is usually performed immediately after hardening, it might be considered as a continuation of the former process.
The work or tool to be tempered is slowly heated to a cherry red and the cutting end is then dipped into water to a depth of 1/2 to 3/4 inch above the point (Figure 6). As soon as the point cools, still leaving the tool red above the part in water, remove the work from the bath and quickly rub the end with a fine emery cloth.
As the heat from the uncooled part gradually heats the point again, the color of the polished portion changes rapidly. When a certain color is reached, the tool should be completely immersed in the water until cold.
For lathe, planer, shaper and slotter tools, this color should be a light straw.
Reamers and taps should be cooled from an ordinary straw color.
Drills, punches and wood working tools should have a brown color.
Blue or light purple is right for cold chisels and screwdrivers.
Dark blue should be reached for springs and wood saws.
Darker colors than this, ranging through green and gray, denote that the piece has reached its ordinary temper, that is, it is partially annealed.
After properly hardening a spring by dipping in lard or fish oil, it should be held over a fire while still wet with the oil. The oil takes fire and burns off, properly tempering the spring.
Remember that self-hardening steels must never be dipped in water, and always remember for all work requiring degrees of heat, that the more carbon, the less heat.
Article Source: http://www.articlesbase.com/business-articles/tempering-metals-247627.html
About the Author:This article was an exerpt from "The Welding Bible" . The Welding Bible is your complete source of methods, charts and information about gas and arc welding, brazing, cutting and properties of metals.

Author: Eren Bengu
Forging, one of the oldest known metal-forming operations, has come a long way since the days of banging hot steel by hand. However, the fundamental process has remained the same for thousands of years. In every situation, forging involves the application of a compressive stress, which exceeds the flow stress of the metal.

The forging process typically begins with a standard billet, with the objective change its dimensions. In its more sophisticated form it produces complex shapes to a very high degree of accuracy. Forging can either be applied quickly or slowly. The process can be carried out hot or cold. Depending on whether the operation is carried out hot, or cold, forging affects the structure and properties of the forged component to varying degrees. There are two kinds of forging process, impact forging and press forging. In the former, the load is applied by impact, and deformation takes place over a very short time. Press forging, involves the gradual build up of pressure to cause the metal to yield.

Impact forging can be further subdivided into three types:

-Smith Forging
-Drop Forging
-Upset Forging

Smith forging is the oldest type of forging, but it is now relatively unused and considered outdated for most applications. The impact force for deformation of steel is applied manually by the blacksmith by means of a hammer. While being hammered the metal is held with suitable tongs to protect the blacksmith from the excessive heat required to forge the steel.

Drop forging is the modern equivalent of smith forging. limited force of the blacksmith has been replaced by the mechanical hammer. With this system, the quality of products depends on the skill of the worker.

Open forging is used extensively for the cogging process where the work piece is reduced in size by repeated blows as the metal gradually passes under the forge. The objective is to reduce the thickness of the work piece in a stepwise sequence from end to end. Several passes may be required to complete the work and edging is usually carried out to control the width. The reduction in thickness is accompanied by elongation and spreading.

Closed-die drop forging is widely used in modern applications. It requires the dies to have a series of grooves and depressions cut into them, allowing the work piece to pass in sequence through a shaping series. To ensure that the die cavity is completely filled the volume of the starting billet is greater than that of the final forging. The excess metal appears as a "flash", this is a thin fin around the perimeter of the forging at the parting line. This flash is cut away in a further press operation generally at a high temperature. Each size and shape of forging will thus require a separate set of forging and trimming dies.

Upset forging: This process was developed originally to upset metal to form heads on bolts. Today the purpose of this machine has been broadened to include a wide variety of forgings. It is essentially a double-acting press with horizontal motions rather than vertical. The forging machine has two actions. In the first, a movable die travels horizontally towards a similar stationary die. These two dies have semi-circular horizontal grooves, which grip the bars. A bar heated at the end is inserted between the movable and stationary die. While thus held, the end of the bar is upset or pressed into the die cavity by a heading tool mounted on a ram, which moves towards the front of the machine. If hexagon heads are desired, a heading tool will upset some of the metal into a hexagon-shaped die cavity.

Structure and Properties of Forgings: Forgings are invariably produced by the hot-working process and this controls the resultant structure and properties. There are, however, important differences in forgings produced by different techniques. The fact that the impact forge applies a stress for a very short period compared to the long period for the press forge results in totally different structures in the product. In the case of impact, the mechanical working is concentrated in the surface layers, since rapid removal of the stress after the blow results in metal relaxation before the effect of the blow has penetrated into the center. Impact forging of a large "as cast" piece of metal at high temperature will result in a very inhomogeneous structure, the outside layers showing a typical hot-worked structure whilst the center is still as cast. Any attempt to achieve greater penetration by increasing the impact load usually leads to internal cracking. Impact forging is therefore limited to relatively small work pieces.

Press forging invariably results in total penetration of the effect of the applied stress into the center of the work piece. The process is generally less severe on the metal than impact. The end result is a more homogeneous product having very high quality. Since the process is much slower and the equipment used is much larger, press forged articles are more expensive than impact forged components. However, only press forging should be considered for critical steel components.

Modern forging shops generally utilize hyrdraluic, steam or electric powered presses to generate up to thousands of tons of force to quickly and accurately manipulate a custom shape in hot steel. The automotive, railway, construction and aerospace industries require millions of tons of high quality forgings annually. However, there is a limited number of forging facilities capable of producing forgings under the modern processes accepted by very regulated companies.

An example of a large, well-equipped modern forging facility that performs open and closed die hot forging is Yapi-Tek Celik Sanayi in Turkey. This facility provides one of the best examples of a large-scal operation capable of producing high-quality, custom steel forgings . For more information visit www.celiksanayi.com
Article Source: http://www.articlesbase.com/technology-articles/modern-steel-forging-290414.html
About the Author:Turkey-based Yapi-Tek Çelik Sanayi A.S. is a manufacturer of custom and mass-produced hot forged steel products and forging dies. Its current production capacity is 20,000 tons per annum. Established in 1959, Yapi-Tek Çelik Sanayi was the first privately-held forging factory in Turkey. Visit www.celiksanayi.com for more information.