|
True swords are made by skilled smiths |
|
|
|
True Swords Are Made By Skilled Smiths A superior way to balance hardness and toughness is through steel with non-uniform properties. This can be achieved through differential hardening, differential tempering, differential density, differential carburization or through mechanical or crystalline Damascus techniques. Metallurgy is science, but it is also a unique type of art where many techniques may be used to obtain the desired result. Differential Hardening – This technique is seen on traditional Japanese swords, but can also be applied to other designs. It is based on cooling the edge more rapidly than the spine, thus giving the edge a higher hardness. Differential hardening can be accomplished by quenching the edge or by using clay to insulate and retain heat in the spine while quenching the whole piece. Differential Tempering – Applying a lower level of heat to steel removes some of its hardness, giving it added flexibility and toughness. The amount of flexibility or toughness in different parts of the blade can be controlled through differential tempering. Differential Density – Some smiths believe in this technique, while others just as strongly claim that is has no basis or value. In any case, the concept is that the edge of a blade can be packed more densely than the body through hammer blows, thus giving it additional strength and hardness. Differential Carburization – This takes advantage of the fact that every flame has three zones – oxygen rich, neutral and carbon rich – and that, depending on where it is in a flame, steel may either lose or gain carbon at the same rate, to a depth of about 1/8 inch per hour. Used properly, a smith can add carbon to a blade’s edge to increase hardness while retaining the spine’s flexibility. Unfortunately decarburization, the result of inadequate knowledge or training, is a frequent problem that adversely affects the quality of many blades. Mechanical Damascus – This technique combines two or more dissimilar irons or steels through forge welding and then folding or twisting the resulting steel to produce the characteristic Damascus pattern. This is one of the oldest ways of converting iron to steel.
|
